Need Low-Mid PC Build Advice

Hey guys, I was wondering if you would help me with my first entry into gaming PCs. I think what I have in mind is low-mid range and want to know what you think of it or what you would recommend. Specifically, what Im looking for is a PC that will play games like Guild Wars 2, Battlefield 3, The Witcher 2, etc. at 1680x1050 at high to ultra settings with around 30-35+ FPS. My budget is $750 and, unfortunately, it has to include a monitor and OS. Thanks for the help in advance and Ill respond as quickly as I can.

 My build so far:

 

  • MSI 970A-G46 AM3 AMD 970 SATA 6 ATX Motherboard


 

  • AMD Phenom II x4 965 Black Edition 3.4 GHz quad core CPU


 

  • Corsair Vengeance 2x4GB DDR3 1866 RAM


 

  • Sapphire Radeon HD 7770 GHz Edition OC 1GB GDDR5 128-bit GPU


 

  • LEPA 550W 80+ Bronze Certified SLI/Crossfire-ready PSU

 

  • Cooler Master DK9-7E52A-0L-GP CPU Cooler

 

  • APEX SK-393-C Black Steel ATX Mid Tower Case

 

  • ASUS DRW 24X DVD Burner

 

  • Western Digital RE2 750GB 7200 RPM SATA 3 Hard Drive

I would go with this:

http://pcpartpicker.com/p/1VUvO