Aye, Dan is a good guy with a great store.
For heavy music in general, including thrash, death metal, black metal, and other more extreme forms of metal, I can also highly recommend Hellride Music.
My favorite Doom site is Doommantia, btw.
…or we could all just listen to Maggot Brain again.
There’s still a lot of great music that fits the bill for the OP, but I’m also still working 16 hour shifts, so y’all will have to settle for some quick fixes.
For retro arena blues rock with a slightly psychedelic touch, I offer:
For some moderately accessible doom, check out:
hehe I’m letting my crew do all the work today
How about some serious stoner doom psych rock?
All Them Witches. I just found these guys yesterday, and they fit the op to a T.
Ooh… Harsh Toke is new to me. What about Sons of Otis?
Vista Chino. It’s basically Kyuss without Josh Homme, and they’re pretty awesome…
New Kyuss…thanks! That album is on Spotify too 
Listened to the whole album now…Love it! Need to listen at home so I can turn it up a bit 
Brant Bjork and the Operators.
Brant has drummed for Kyuss, Fu Manchu and Queens of the Stone Age.
If you haven’t heard it, Oedipus, you really must listen to the original version of the tune you linked to in the OP.
Well, if we’re going to pull out Neil Young, Hey, Hey, My, My (Into the Black) must be mentioned.
I see the thread won’t die; excellent!
I’m now recovering but I saw the thread still floating and I wanted to offer a couple more recs:
From Los Angeles, here’s Black Prism - Satan’s Country. Doom-y doom. (WARNING: the audio levels are a bit hot on this track; not distorted, just really really hot.)
For pure stoner/desert/groove rock, check out SpiralArms - Dropping Like Flies. Think Wiseblood-era CoC crossed with a pissed-off Kyuss.
And for post-punk/stoner groove so laid back it’s practically in a hammock may I present Whores of Tijuana - Trip Manhattan.
Bonus points if anyone can figure out what those three bands have in common (besides all being in my post, eh! :p). No points awarded after 7 June 2014, natch. 
Check out the first two albums by Deep Purple: “Shades of Deep Purple” and “The Book of Taliesyn”. Some utterly amazing covers of Joe South’s “Hush,” Neil Diamond’s “Kentucky Woman,” and Ike and Tina Turner’s “River Deep, Mountain High.”
The Deep Purple cover of Hush is about the least “slow, heavy” song I can think of.
Wow! I’m surprised with all the attention this has gotten! I can’t believe I forgot about making this thread. I’ve loved a lot of the stuff posted here. Lets just remember to slow it down.
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Too fast - SpiralArms - Dropping Like Flies
and I don’t want to get into a semantics/metal genre argument but these guys seem way too metal for classic psych rock. -
Heavy as shit for what I was looking for originally but great all the same - Electric Wizard - Funeralopolis.
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Beautiful - Dead Meadow - Breeze Always Blows
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Too heavy for the OP, but I shed a tear nonetheless. Candlemass - Solitude
Orchid was alright, but it just didn’t hit a nerve for me, sorry. Black Angels are pretty amazing. Are there a lot more tracks out there like the first one from the album? **Morgen **was pretty awesome from what I heard. Trust me, I listened to a large majority of the links posted, but I can only write up so much and these were the ones that struck me.
Their first two albums are amazing. #3, Phosphene Dream was tighter and slightly more sterile. Their last album, Indigo Meadow was shite: pop songs with a '60s garage rock veneer only.
Okay, if you really like Electric Wizard (and who doesn’t?), maybe you’re ready for stuff like
Acrimony - Hymns To The Stone (awesome Welsh stoner/doom outfit)
Belzebong (seriously stoned doom from Poland)
Bongzilla (seriously stoned doom from Madison, Wisconsin)
Church Of Misery (the best Japanese doom band from Tokyo that sings almost exclusively about serial killers, ever)
Master Of Brutality (John Wayne Gacy)
Cities On Flame With Rock And Roll
Conan (doom from Liverpool, England, UK)
Cough (extreme doomsters from Richmond, VA)
Mind Collapse
A Year In Suffering
I’m only up to C but I’m getting sleepy and if I’m gonna go and mention Cough I might was well mention what is generally acknowledged as one of the finest, if not the finest, American doom bands ever:
YOB (drone doom masters!; one of my favorite bands)
Adrift In The Ocean
Prepare The Ground
Gotta sleep now. G’night.