Just Want to play games like Crysis or GTAIV in 40 frames up..
would this be a good build for the budget of a $1200 USD?
NEVER get a rosewill PSU. They suck. THEY SUCK!
Also, the case was the deal of the day either yesterday or the day before. You could've saved 10$. Go with Ssassan's rig. It'll do fine in Crysis but don't get a 4850x2 when you can get a 4890 (or GTX 275) for the same price. One GPU beats two smashed together in plastic casing. Good luck.