As said above, an aftermarket CPU cooler is never a bad idea. I've had a i5 2500k clocked at 4.9ghz since launch with a noctua cooler and the other half has a i7 2600k at stock and mine is quiter when gaming.
PSU isn't something to save on, you don't need more than about 600w with this build, so the 750 covers it. I've always built with Corsair PSU's and found them ridiculously reliable, the modular ones make for a very tidy build also.
Lastly, I'm no card fanboy either, I've always gone with the best performance or feature set for the price at the time of a build. That Radeon is every bit as good as a 680, in some games one will win, in others the other will win. And we currently own two 680's.
The only advice I can give on the GPU is if you game a lot and plan to get a 120hz monitor AMD/Radeon isn't even a consideration right now over Nvidia because of the current Lightboost hack you can do on 680's with 3d 120hz monitors.
Research this lightboost stuff a little and see if eliminating motion blur is important to you at the cost of a little screen brightness. It's a bit like running a nice current gen plasma tv, aka 1000 lines of motion resolution at the cost of not looking great in a very bright direct sunlight room.
