Have you thought about using a Lehmann Audio BCL (£750) to drive the HD800's?
Doesn't help wi the DAC part of your quandary but I understand that the BCL was part-used to develop the HD800 and certainly is a good a good match for them.
DAC wise, I've heard good things about the Audiolab M-DAC (£599 and thinking of getting one myself actually) and Arcam's rDAC is good at £325.
I'm in UK so not sure what availability for the above brands/models will be like across the pond as I'm assuming you're in the US.
Thanks for the suggestions, but for now I think I'm going to spend a little less than that. I am going to give the Schiit gear a try. If I don't like it I don't think it would be too hard to sell and replace with something else.