Damn, you're on a pretty tight budget there. I would say go for AMD graphics cards, they have more bang per buck and since u dont have too much money on your hands, that fits you well. I don't know too much about AMD cards, I normally have a larger budget and I always get NVidia. Also, I would get 4-8 gigs of ram, and as for your motherboard, you need to determine what size mb and case you want.