I would not consider the GTX 460 slow, not when its overclocked, Also, the motherboard I have chosen is highly rated and has good feedback from alot of users. Remember, i'll only be at 1680x1050 res for a while, the 460 will handle that with ease.
I am however, umming and ahing over cooling for the processor and a different case. Ideally, would like a reasonably quiet experience so any help there would be appreciated