DONT use a ASRock 775XFIRE-ESATA2 LGA775. It was the cheapest board with these specs on ebay except it wont boot with any AMD/ATI card I've put in it. Even booting with any nVidia card (all of which worked), I still cant even see any AMD/ATI cards connected on 1x or 16x.
It might just be my board, but for sure they are all really finicky about memory. Mine wont boot with two matched 1GB sticks, but will with one of them pulled out.
I've heard the ConRoe version of this same board will work but I haven't tried it myself.
Definintely finicky about memory. Didn't like any of my sticks I had already. Had to swap back to my old board and ended up wasting a couple doses of IC Diamond.