If you are overclocking, then make sure to get a CPU cooler.
Antec, Corsair, Seasonic, and XFX make good units. You should be fine with 500-550W if you don't plan to Corssfire in the future.
Okay, I plan to overclock next month when I get the cooler master 212 Eco for Christmas, so for the time being I use the stock cooler. I don't plan to get another one, I always hear bad things about SLI/crossfire so in like 3-4 years when I need to upgrade I'll a new gpu. I heard seasonic are best brand for power supply's. Are you able to post any links? I don't want to buy one and find out it not enough power