The build looks fine to me, though what I would suggest is going for one of the new Asus motherboards, they have something called UEFI for their bios, which is much better than the standard at the moment.
Advantages: You can use the mouse to navigate through (which is really weird for me being so used to using the keyboard), and is also a lot quicker to load than the standard bios.
UEFI has only started making it to home computers recently, and as far as I've seen, Gigabyte has no support for it, whereas Asus does.
Also, if you're rich enough, consider grabbing an SSD, no point spending heaps of cash on a good processor, RAM and good Graphics Card if your system is bottlenecked by your HDD. And is the HDD 32mb cache, or 64mb cache... and I assume 7200RPM?
Just some friendly suggestions