1) Are parts compatible?
2) Which part will bottleneck first?
3) Will mobo fit card? I heard small mobos had trouble with big cards
4) PSU = power needs or should I consider changing it?
5) Any special cooling considerations to consider?
6) I'm not 100% on the mobo. Es bien?
1.) Yes, except for the case, as stated. EDIT: Nope, I lied, PSU is also ATX rather than mATX.
2.) GPU, although both it and the CPU are middle-of-the-road (so far as gaming is concerned) choices.
3.) Yes, it has a PCI 2 slot... but remove the "Maybe" from the question about Crossfiring = single PCI means single card.
4.) The PSU is actually quite a bit over what you need, if you're only going to have a single 5770.
5.) If you aren't overclocking, no... so long as you get a good case.
6.) It's respectable, again, if you plan on only ever having one GPU.