If you're overclocking, no point in getting a i7-950. For pure gaming actually, any i7 is useless. You're paying money for useless threads. Gaming isn't well threaded at all, and doesn't really benefit from more than 3.
Get an i5-750 for gaming.
You can't xfire a 6xxx gpu and 5xxx gpu. Well, I guess you could try(assuming drivers even allow it), but the 6xxx would just run at the speeds of the 5xxx, so you're effectively paying more money for less.
Avoid 1.65v ram. You're better off with a G Skill Pi 1600 cas 7 kit.
Asrock is a budget mobo company. For the same cost you're better off with a GA-x58-UD3R.
You also didn't list an optical, but you can just pick up cheapest burner you can find.