I like Atticus.
And I think I’ve heard of Sebastian being shortened to Seb.
Others to consider:
Virgil (Can’t go wrong with an Earp name.)
Grover (Yes, yes, the Muppet. Or the President. Two stalwart individuals who’ve established a fine tradition!)
As your older child has a scottish (middle) name, I would go with another Scottish name. Duncan, Hamish, Callum, Ian. I think all of those sound good with Phillip too, I always reckon siblings names should kinda gel with each other.
Atticus and Phillip…hmmmmm
I’m loving Duncan (but keep thinking about doughnuts…)
I like Quinn - good name, and BONUS!! You get to sing about Quinn the Eskimo for the rest of his life (When Quinn the Eskimo gets here, all the people gonna run to him. Come on without, come on within. You’ll not see nothing like The Mighty Quinn.)
Yep, Quinn 
How about Owen?
Ian is actually one I considered calm kiwi, except my older sister threatened me with death if I stole it. She’s been hoarding it since we were teenagers and would never forgive me!
I knew an Owen in grade school who was a total shit, so that one’s kind of ruined for me. Which is too bad because it’s one I’d otherwise really like–simple but still classy.
I just thought of a couple others I should have had on my list, what’s everybody think of “Elliot” or “Lucien”?
And Interrobang—Virgil is a good one, my Latin teacher would be so proud of me. But Grover!? Oscar I could do just because at least the grouch is cool, but Grover was the lamest muppet ever! 
[sub]please don’t let anyone reading this be named Grover ::cringe::[/sub]
LOL don’t ya just hate people that hoard the good names
Elliot is really nice…oh and siblings with double “l” names, that’s a whole other theme. 
Very sad you didn’t like Callum, that’s my sons name 
I vote for Augustus—but only because he was my favorite character in Lonesome Dove
The lamest muppet ever was either Kermit’s nephew or the bunny. Period.
Anyway: first off, impending congratulations. Maybe it’s me, but this is hard to judge without a last name, since the flow of a name is a big deal.
I have a friend named Quinn, and I think it’s a good name. I hope it doesn’t get popular. I think Quinn James works okay. Although, DeVena, it may not be her cup of meat.
A lot of the others are very unique, but they’re not necessarily something I’d want to saddle a kid with - like Wolfgang or Atticus or Gideon or Augustus. Strikes me like the kind of name a parent would use to draw attention to his/her own intelligence. “You must respect my intelligence and worldliness- I named my child Wolfgang! Of course, unless he grows up to be a famous composer or a chef, he’ll be totally miserable.”
Okay, that was a random riff for my own amusement. But maybe you know what I’m getting at. I’d never be able to take a Wolfgang seriously (unless he was German), and that’s coming from a guy named Marley. K?
Random other tip: I guess you’re Scottish, given the names you’re picking. Careful about overplaying that card. My friends Mary Kate Shannon and Kelly Bridget O’Sullivan get teased a bit. [These are real names.] “How Irish can ye get, already?”
You’ve actually got a couple of surnames on there- Zane, Maxwell, Sebastian, Baxter maybe.
How is Xaden pronounced? I guess the X becomes a Z sound, but I think “Shaden” (soft a) sounds cool. You may not want to name your kid for a videogame, though.
Much as I like Atticus, I just had a vision of Al Pacino inciting a crowd by chanting “Att-i-cus! Att-i-cus!” over and over again. (That’d be a movie –_TKAM meets Dog Day Afternoon.)
My work here is done.
(Oh, and Lucien is nice.)
Actually, Marley , I’m Polish–which is where Lucien, Otto, Sebastian, and Augustus all come from. But Boleslaw, Stanislaus, and Ignacy don’t really do much for me.
The father does has a scoonch of Scottish in him–Malcolm was a family name on his side and he just got lucky because it was one I liked. This time though, I’m getting complete naming authority and instead of being easier, like I thought it’d be, it’s actually harder because there’s no one to veto any and trim the list down!
And I do know what you’re saying about some of the names being maybe a bit over the top. I like strong names, and my own is one that I’ve never come across before IRL, but at the same time I don’t want to impose anything cruel on a kid. So thanks for the opinions–from everyone. They’re much appreciated and I’m obsessively refreshing this thread because every response is helping me look at my list objectively.
Cheers!
1st impressions
Jasper - the name my 4 year old cousin used when
he was pretending to be a dog.
Quinn - too medicine womanish
Simon - I like this one
Zane - only if he’s going to write Westerns
Sebastian = I like this one too. Reminds me of
the little kid in Neverending Story.
Augustus (Gus) - All hail the Emporer!
Oscar - gotta go with the Grouch
Baxter - too last name-ish
Gideon - somebody else said something about Bibles?
Atticus - Oddly enough, my fist thought wasn’t TKAM,
but Sparticus with Paul Newman.
Duncan - I like this one too. Nice, solid, and Scottish!
Wolfgang - Ever seen Amadeus? Mozart’s wife calls him
Wolfi in an irritating high pitched tone - I’m a no.
Xaden - interesting, but I think it sounds a little too
D&D for my taste (I’ve got a friend who named her daughter
after one of her RPG characters - she’ll never live it down!)
Otto - I’m with the Simpsons reference
Malachi - my favorite of the bunch. Traditional, strong,
different.
Maxwell - coffee anyone?
As an additional suggestion, what about Mathias? A good
name, and easily shortened to Mat or Matty.
You do have a lot of good strong names chosen. I particularly like the names that have a good short nickname, like Augustus. That gives him a name he can be a kid with, and later, if he wants to go by a longer, more dignified-sounding name, he can. I know a 7-year old Benjamin who chooses to use the long version though.
Maxwell is my favorite - my second son is a Maxwell Seamus. We’ve never heard a coffee reference!
From the list, I like:
Jasper
Duncan
and, maybe, Quinn.
Not too odd,
not too “foreign,” (i.e. incongruous with the last name)
not too macho,
not too ambiguous,
no instant associations (a la Gideon or Wolfgang)
so, interesting but less likely to engender teasing or be a burden in the schoolyard.
My personal favorite not on the list: Cooper.
If Ian is out, how about Aidan? (our family has an unofficial no-hoarding rule, though we generally respect longer-term preferences… but Aidan was on my list, and my sister had her son before mine - birth order trumps all, and no hard feelings, as it is the definite right name for her son, and wouldn’t have worked for mine).
Brendan? Though one warning on that one - you’ll get girl comments (people hearing ‘Brenda’) and loads of mistaken spellings (Brandon, Brennan, Branden, Brendon… AHHH!). More Irish than Scots, though.
Polish-usable options:
Aleksander (yeah, funky spelling, but I like it)
Ambrose
Bendek (var. Benedict)
Daniel (Daniel and Phillip works for me)
Jacek
Konrad
Nathan
Samuel
Thadeus/Tadeuz
Scottish-usable options:
Alistair
Broderic (might be too last-name-ish)
Cameron
Dougal
Fergus (Gus again…)
Gordon
Marcus
Nicholas
Nathaniel
Timothy (classic, not sure how common any more)
I’d vote for Jasper, Duncan, Maxwell, or Lucien. Here are my opinions on all of the names, sorry if I sound harsh or insult anyone’s favorite name.
Jasper - I really like this name. It’s not overly macho, but it’s clearly a boy’s name. However, with Jasper James you might find yourself with a “J.J.” since your family is fond of nicknames like that.
Quinn - Everyone’s mentioned the tv show, and everyone always will with this name.
Simon - An ok name, but it seems kind of nerdy to me, probably because of the sibilant S. He’d have to be very cool to carry this name.
Zane - This will probably be a girl’s name in twenty years.
Sebastian - An ok name, but only with the Bastian nickname, and that does invite teasing.
Augustus (Gus) - I just don’t like the Gus nickname, nor Auggie. The full name is nice though. This is sort of a “middle-name” type name to me, but you already have a middle name for him.
Oscar - hot dogs and garbage cans, sorry.
Baxter - Baxter means “baker woman” but with all the little girls named McKayla and Carson, I don’t think meaning really matters anymore.
Gideon - Haven’t heard Gideon as a baby name before. Hmmm, not too bad, wish it had a nickname though. It’d be awful for you to put all this thought into choosing his name and find that he’s been nicknamed “Giddy” by his classmates.
Atticus - I love this name, and am going to use it a middle name someday. I think it’s a lot for anyone to live up to as a first name though, and it has no nickname, as others have mentioned.
Duncan - Great name. Most people haven’t seen Highlander, so I don’t think that will be mentioned very often. Again, you might want to be sure your family doesn’t make this one D.J.
Wolfgang - I like this name, especially with the Wolfie nickname, but no one else seems to 
Xaden - Very awful.
Otto - I kind of like it, it sounds cute and new for a kid. And it’s a palindrome, like Hannah.
Malachi - I’m not fond of it, but it’s an ok name. There’s a children’s book by Eleanor Estes, The Witch Family, where Malachi the Bee is the hero. He might like to read that someday.
Maxwell - A very good name. Max has been a really trendy name for the last few years, but it’s a solid enough name that it can survive the trendiness.
Elliot - A decent name, but he’ll have trouble with the number of L’s and T’s his entire life.
Lucien - Cool unusual name. Seems kind of Matrix-y to me for some reason.
Virgil - middle-name material.
Grover - I loved Grover! It is more of a pet’s name than a child’s though.
Let’s see… my impressions? (popularity ratings are from my copy of Janet Schwegel’s The Babvy Name Countdown)
Jasper - hey, it’s a precious stone! (0.11 per thousand babies)
Quinn - not too bad… I like this one (0.32 per thousand)
Simon - definitely classic… (0.86 per thousand)
Zane - reminds me of the word “zany”… could be good, or bad, depending (0.30 per thousand)
Sebastian = I like this name a lot… reminds me of the old TV show “Belle and Sebastian.” Used to actually know a kid named Sebastian in elementary school, too. (0.67 per thousand)
Augustus (Gus) - reminds me of Caesar Augustus (0.06 per thousand)
Oscar - either the Grouch or the playwright Wilde (1.42 per thousand)
Baxter - my friend G named his own kid this about two months ago… but if you don’t like last names ending in “er” as first names, this may not be for you (0.01 per thousand)
Gideon - the Biblical character… (0.05 per thousand)
Atticus - definitely my first impression would be TKAM (0.01 per thousand)
Duncan - I like this one… I’ve only ever known one Duncan in my whole life, also in elementary school. A nice Scottish name, too… most probable nickname out’ve this one will be “Dunc.” (0.26 per thousand)
Wolfgang - Mozart… this is also what Eddie Van Halen and Valerie Bertinelli named their son (0.03 per thousand)
Xaden - Hmm… interesting name… sounds a bit too RPG’ish for my taste. That would be like my naming my kids (if I ever had any) Brolx, Ragnar, Cristo, Alena, etc. (nup… not in the book, perhaps understandably!)
Otto - Simpsons (0.03 per thousand)
Malachi - the Biblical book; also Malachy McCourt (the author Frank McCourt’s younger brother)… doesn’t strike me as a “kid” name, though… but it IS different, if that’s what you want (0.11 per thousand)
Maxwell - also makes me think of coffee (0.79 per thousand)
F_X
From the list I’d have to go with either Duncan or Sebastian. If you went with Max I’d have to stress Maximillian rather than Maxwell. How about Balthazar? I like Aidan, or Alistair, or Declan, or Liam. If you’re concerned about the current gender-neutralness of Quinn you could go with the Irish Quinlan instead.
Good luck!!!
-BK
Those are the names I think go best with Philip. Solid manly names, that aren’t too much of a reach. And I think any little boy or for that matter 18 year old young man with one of these names would have to be a very cool person.
Twiddle
I like Atticus but it’s hard to shorten. I love Gus but got outvoted. Quinn is becoming very popular with boys and girls.
Mr P desperately wanted P the Younger to be called Jasper but it’s hard to shorten unless you like Jas. Which I don’t. Sebastian is sometimes shortened to Bas here in NZ and Australia.
Max is a good name. Not so much Maxwell though. I’m a Maximillian fan although we just used Max for the P the Elder.
Balthazar? I don’t think you should name a kid anything that sounds like it’s from DnD. Actually, someone in Baldur’s Gate II was named that, IIRC.
Maximillian? Only if kiddo is going to be “The Third” or an Emporer of some kind.