Cut the PSU to a 650 watt and use the extra money to upgrade the GPU to a 760. --- Humankind cannot gain anything without first giving something in return. To obtain, something of equal value must be lost.
For almost the same price as 660, you could get an R9 270x which is much superior in performance. Your psu is overkill. You can get a sufficient one for far cheaper --- ---lololololololololololololololololololololololololololololololololololololo ---ololololololololololololololololololololololololololololololololololololol
Everyone's suggestions have been good. I would recommend getting Windows 8 and downgrade it to Windows 7 Professional which I did. That way, if you have an inkling to upgrade to Windows 8, you have that option.
I think Corsair PSUs are fine.
Are you planning on overclocking? The CPU and Mobo suggests you are. You may want to think about a good CPU heat sink. But stock CPU is fine until you want to overclock in the future.
--- PSN, XBL & Steam: juscallmeehx i5-4670k CPU @ 3.7GHz OC | 2x8GB RAM | Evga GTX 560 ti | 2x128GB SSD & 1TB HD