I personally think you're spending too much on the video card. Even though it states rebate, It would only be a deal if you actually receive the rebate. It outwieghts your main component, which is the cpu. Your CPU will be the bottleneck for that card. I would personally, get a 6600GT for like $130, an Arctic NV Silencer and overclocked it. Atleast you'll have a performance balance in your system between the 2 main components.
I also would've purchased the Epox KT880 from mWave for $7 more. Faster than the board you selected. Again, this is all my opinion, I could be wrong.
When you finish building the system post back a summary, with results.