CPUs are hardly ever the bottleneck. I would say the most likely bottlenck in the system would be the GPU, then maybe the RAM.
You still don't have a CPU cooler. And you won't find one cheaper than $6, the difference between the version that has a cooler and the one that doesn't.
You should switch the DVD burner to the one I posted. You'll save $10 one the price+shipping and lose absolutely nothing in performance.
Switch the Seagate for a Samsung Spinpoint F3 500 GB for the same price. The F3 is slightly better. If that's sold out, the Seagate's the best alternative.
I still hate that PSU. I use this ranking system for all PSU recommendations. It's generally not advised to stray below tier 2. Coolmax 750W+ units are tier 2, but all others are tier 5 (the worst). If you can squeak an extra $25 out of the build, the OCZ StealthXStream 700W is very powerful, quality, and cheap at $50 after rebate.