Edit... Just noticed this build is for May, so please revisit the build a week or two prior to actual purchase date to make sure it is still your best option. Prices change and with some new stuff coming out in April, could effect your purchasing decision.
Your build looks cool! Heavy gamer r u?
Btw, i too prefer Seagate over W.D, especially for the 500GB. Seagate Barracuda 7200.12 500GB gives good performance for gaming.
And as tecmo said, check for prices and other models just a week before you buy. While i dont advice buying any new models that come in april, a month-and-half wait may have some price reductions, so you can buy a little higher models in Mobo, Case, etc.
On the other hand, if the prices go up by a few notches (could happen), my tip for u is to cut off the 6GB RAM to 4GB (which is good enough now), and add in extra memory when the prices go down. RAM prices are very high now!
I'm looking at a very similar build. Any concern with the X58A-UD3R not having support for the i7-930 until BIOS version F4? I'm not sure what BIOS version it's shipping with but I assume F1. Will this present any issues?