I have no specific problem with “Porter”, except you’ve suggested it to someone named Potter.
Porter Potter.
Not only do I dislike the sound of those names in combination, but it sounds a lot like Porta-Potty, which is what we call those portable toilets that they use on construction sites. 
Congratulations, Abuse Angel!
Names… I love the boy’s name Riley… can’t define why, I just love it! Ideally, I’d name my son Riley Thomas B______, but I’m having a hard time convincing Mr Cazzle that this is a good idea (not that we need baby names just now). I was going to suggest Riley Gerald because that’s his grandfather’s name and might help reconcile Mr Cazzle to the idea. I’m not keen on Gerald, but Mr Cazzle likes it. Other family names we’re considering are Graeme, Douglas and Donald.
Girls names - I love Alanna. I pronounce it ah-lah-nah, not al-lan-nah. I also like Alyssa, however you choose to spell it, and Maegan (May-gan, rather than Mee-gan). I have a cousin called Elliana, and I think that’s a most beautiful name.
I dislike aliteration in names. SO’s cousin had a baby recently named Cooper Charlie Corbett. Yech. Not my taste. I personally love the name Isobel, but crossed it off my list because I think the “B” sound is too hard to repeat in a name - my future married name sounds like Beckham. Isobel Beckham doesn’t sound right to me. Mr Cazzle commented that Rebecca is a nice name (it is), but I pointed out that Rebecca (Becky) Beckham sounds awful. I also don’t like initials that spell something. All in all, I’m going to be walking a naming tightrope!! Something to honour an ancestor, something without a B in it, something fairly conventional to please Mr Cazzle, something that doesn’t spell out anything in the initials, something old, something new, something borrowed… oh, wait. Where was I?
Just a suggestion - the Unusual and Creative Names Page. It may be helpful, or it may just be good for a laugh. Let me tell you, it takes all kinds! Some of the names suggested on that site are downright horrifying!! Others are cool.
I knew of a girl named Lorelei, and I always thought it a pretty name.
Just a final note - Harry Potter’s parents in the book are Lily and James Potter. He has no siblings, so these are the only other names you need to worry about if you want to steer clear of JK Rowlings characters 