A stock GTX 480 requires a 600W PSU with a minimum of 42A on the 12V rails and (1) 6-pin PCIe connector and (1) 8-pin PCIe connector. This PSU meets the minimum requirements for your config, but your OCs will push this PSU hard during high power usage situations; stress test or intensive gaming. It's a great deal on that PSU at $35 I would go for it and stress test it with Prime95/Furmark to verify stability. If it doesn't work out, then RMA and get a better quality unit with a bit more beef on the 12V rails.
A stock GTX480 is a 250W part. Add in another 150W for the OC'd CPU and you are only at 400W. Even if the rest of the system needs another 50W, you still have nearly an extra 200W left over. He's got plenty of power.
I was basing my inputs on the cards requirements. I completely agree that PCs typically don't get near those stated requirements and a good 500-550W will handle nearly any single-GPU system. In the real world, he'll have some decent headroom. That 400W + other system draw doesn't include the OC for the GTX480. Depending on how hard he pushes the GPU OC he could see power draw reach 450-500W and that PSU can provide up to 576W on the 12V rails.