Upgrade help and GTX 680 SLI/ PSU question?

My PC has the follwoing specs below that I would like to upgrade. I want to know if my current configuration can handle another GTX 680 for SLI as I already have ordered another GTX 680 as my first upgrade. In addition what would be good to see a noticable imporvement with the motherboard, processor, cpu cooler, ram (if needed), and PSU (if needed). I know this is random but I noticed a lot of screen tearing in Crysis 3 with Vsync on, any suggestions? (I have a 1600p monitor)

I was thinking of buying the Intel core i&-3770K http://www.newegg.com/Product/Product.aspx?Item=N82E16819116501 and  the Gigabyte GA-Z77X-UD4H motherboard  http://www.newegg.com/Product/Product.aspx?Item=N82E16813128583

EVGA P55 FTW motherboard

Intel Core i5 750 2.66GHz LGA 1156 Quad-Core Processor (8MB L3 Cache)

Megahalems Rev.B cpu cooler

PNY VCGGTX680XPB GeForce GTX 680 2GB 256-bit GDDR5

750 Watt Corsair PSU TX750W

8GB Corsair Dominator DDR3 1600Mhz (4x 2GB) Dual Channel Memory

(hardrives, sound card, and case do need upgrading)

Thanks for your help.