id ditch the rosewill psu and get something higher quality. If you want to eventually support dual gtx 570's, i would recommend:http://www.newegg.com/Product/Product.aspx?Item=N82E16817151100&cm_re=seasonic_power_supply-_-17-151-100-_-Product
or this if you absolutely need something cooler looking:http://www.newegg.com/Product/Product.aspx?Item=N82E16817139022&Tpk=tx%20850
in terms of the ram, cpu, and gpu, you could get almost identical performance spending considerably less money. DDR3 1600 will be plenty, you really need not spend over $100 on 8gb (Id recommend.
An hd6950 probably gives you better bang for buck, especially if youre planning a dual card setup, due to superior scaling. However, I dont really have an objection with the gpu if you can afford it. The ram should be downgraded however. Id recommend something like this:http://www.newegg.com/Product/Product.aspx?Item=N82E16820231445&cm_re=gskill_ripjaws_1600-_-20-231-445-_-Product
Consider a samsung spinpoint f3 1tb HDD. It performs as well or better than the caviar black for cheaper (the 6gb/s interface is largely useless for HDDs, due to spindle rate limitations)