As you won't be overclocking, you won't need a new cpu heatsink, unless the stock one is too loud for you. Then as always, I recommend the Cooler Master 212 EVO. For memory, you should at least get a speed of 1600mhz as 1066 will limit your bandwidth. I have two of those gpus in SLI and like them a lot, I recommend it highly. As for the power supply, I only go with Seasonic and only recommend them. You will not regret buying a good one. Do you already have a copy of Windows? If not, don't forget to get one (a OEM 64 bit of 7). I think you if you can change those things and stay within your budget you will have a solid build.
You don't need a CPU cooler if you won't overclock, mATX is a waste in an ATX case, the memory was too slow, and the PSU sucked.
Sorry, though the other thread was the primary one. Guess I was wrong.
EDIT: Also, PCI is much faster than USB 2.0.
thinks to self: yes yes yes yes yes yes yes. hmm no problems here, next post.
But honsetly hes right. while 1066 vs 1600mhz wont make a difference to fps or whatnot, but its just good to have. its only what £3 more expensive anyways.
and dont get bad psus they can damage system parts or just not work, best is that they are less than given rates
listen to this guy OP, hes got it right