Don't buy a video card.
The game is broken. I've got 3.4GHz, 128 of video, with 1.0G of PC4200, and I'm still crashing to desktop and BSODing all over the place. Called the Tech Support people, they can't help me. I'm supposed to call back tomorrow and give them my case # as they try to figure out what's going on.
Wait until a patch is released, and if that fixes anything --big IF-- then try it again, but don't go tossing good money after bad. Your domestic advisor would frown upon this.
Later!
--The Clown to the Left