I thought the HD 800 worked great through the Violectric HPA100. It's a good, clear, resolving amp but no real powerhouse by current standards (It's also versatile: I've used it happily for everything from IEMs through the HE-6). It might be a good option if you haven't got the budget for a tube amp that complements the HD 800 adequately.
Yeah I dont quite have balancing act sort of money to spend, and while I like tubes I am pretty sensitive to distortion and would want to keep the microdynamic prowess of the hd800. Apparently mjolnir is meant to be a good pairing, and that is very affordable, just sounded a bit forward and edgy when I tested a brand new unit with my he6. I could also ditch my dac and slowly shuffle away from the AudioGD gear as I dont trust their digital designs.