You probably want 6 GB of RAM, as the i7-930 runs triple-channel memory. Theoretically, you'll get a little more performance out of RAM with lower CAS Latency...you should be able to get 1600 MHz CL7 G.Skill ECO Series or Ripjaws for $103.
I'm unsure on the motherboard, it might prove forward-looking to get one with USB 3.0 & SATA 6.0 Gb/s support like this Gigabyte UD3R.
The i7 isn't really necessary for gaming-focused builds, it's likely that you'd see the same performance out of an i5-750/760 build for $150-200 less.
Other than that, it looks decent, though you could clearly spend less on the case if you chose to.