You can fit any GPU into the CM 690 case. If you go nvidia you lose the ability to run SLI. To be honest for most people a 1GB 4870 is going to be overkill, I'd recommend starting off with a 1GB 4870 and if or when you need more get a second. Other wise, either of these videocards would be fine and fit into your budget.This looks amazing, I was wondering if we could fit in a Nvidia graphics card