Your build looks good overall, get the ASRock Extreme 3 Gen 3 however due to better power phase giving you better OC'ing.
As far as HDD's are concerned, i just get the best priced one per GB. Prices are too high to make it worth getting much. I got lucky the other day and got a 2TB external USB 3.0 for $99.99.
If you can fit one in your budget, get a small SSD just for the OS. 60gb should do fine for the OS and a few apps.