I recently got the HD800 as well. Got it for $890 new from that Amazon sale. I hope you got it for far cheaper after all the hoops you had to jump through.
Anyways, I had already spend way more than I should this holiday season, so I wasn't looking to get a new amp, but to use existing gear. I had the Bottlehead Crack already, and it pairs decently with the HD800, compared to solid state amps. However, even then, I still found it to sound a bit reserved and polite for livelier music like rock or pop. On a whim, I added my Bottlehead Quickie preamp to the chain, and to my surprise the sound became something else. I found it to have a lot more body and weight, and sound a lot lusher. Overall, I'm pretty happy with the sound. For about $400, I haven't heard of any other well praised amp for the HD800.
I made some interesting observations after some playing around with my chain and various headphones. I found the Quickie to really pull the weight in my chain, and that even Quickie + solid state amp sounds better than Crack alone. You can read about it here if you're interested: http://www.head-fi.org/t/607079/beyerdynamic-t90-d/1395#post_10124880