I have the Corsair TX650 and a 1 X 4850 - they both work great but my PSU is 100W over-kill. For gaming on a single GPU, the TX550W is probably enough. Also, I would go with a P45 MB (such as P5Q). P45 gets you better OCing down the road if you try to get longer life out of your CPU. I just have not seen any advantage to the P43 MB's (really, not even cost).