Nice pc, if you want to future proof your self wait for the q9450, but other than that you are fine. I have the same gpu and it kicks a$$, I am holding it back with my amd 3700 but your pc will chew through games.
The Akasa PSU is a brand I am not familiar with, but looking at the specs, it looks like it can deliver at most 24a at 12v. That is marginal at best for your vga card. I would suggest the corsair 550VX which has a 41a 12v rail.
The rest of the parts look very nice.
Onboard sound is very good; try it first, you can always add a sound card later.
For gaming, the E8400 is better than a quad unless your game is optimized for more than 2 cores like FSX.