I concur with your build except....the mobo. Never ever buy less than the best. Buying the best provides you with so many options later on. You be glad you spent the extra in the beginning and not another mobo later. I suggest the Asus Nvidia 680i (or whatever its called). Good to hear you didn't get suckered into the e6400. If possible you'd want to go to the e6600, but if you can't by all means stick with the e6300.
The (Quad-Core Supports) Asus P5N-E nForce 650i SLI Chipset LGA775 FSB1333 DDR2 Mainboard()[+43]More ... Looks like pretty good bang for the buck. Should be very overclockable and gives you one of the "new" chipsets with SLI as an option. If money isn't that big of a concern I'd go for the EVGA 680i just for the extra ports/options on the mobo.
If price is concern in the least the 650i looks like a good deal at only $23 more than the one you picked.
Your better off building it your self,! Its not hard,and you can get it the way you want it.You also get the satisfaction of knowing thats its your build and not some one elses. For the money your going to spend,you could build a faster machine.
You may be right. I am a former phone tech for gateway and my son is certifide in computers. He is coming home from Afghanistan in a couple of weeks. He gets free windows software being the guard. He is a computer network specialist. I much would I save?