What card should I choose between 660 or 650 ti

This is a build that I am currently setting up with my grandfather I was wondering what Graphics Card you recommend.

APPROXIMATE PURCHASE DATE: Did the math from my job, and birthday coming up that I should have the money for my whole build early December. (900-Range)

USAGE FROM MOST TO LEAST IMPORTANT: Playing Games such as Skyrim, SWTOR, GTAV(When it comes out), TESO, ARMA III, DAYZ (standalone when it comes out) and Minecraft at Ultra or Max settings doesn't matter too much to me. Then Video Editing, Surfing the Web, and working in UDK.

CURRENT GPU AND POWER
SUPPLY: N/A

OTHER RELEVANT SYSTEM SPECS: Here are the other specs of my whole build: (I was wondering if someone could be able to tell me if my PSU is good also.)

Mobo: ASRock Z77 Extreme4 LGA 1155
OS: Microsoft Windows 7 Home Premium SP1 64-bit - OEM
RAM: G.SKILL Ripjaws X Series 8GB
Hard Drive: Western Digital WD Blue WD5000AAKX 500GB
PSU: OCZ ModXStream Pro 600W Modular High Performance Power Supply compatible with Intel Sandybridge Core i3 i5 i7 and AMD Phenom
CPU: Intel Core i5-3570K Ivy Bridge
DVD Drive: ASUS DRW-24B1ST/BLK/B/AS Black SATA 24X DVD Burner - Bulk - OEM
Case: Antec Nine Hundred Black Steel ATX Mid Tower Computer Case with Upgraded USB 3.0

PREFERRED WEBSITE(S) FOR PARTS:New Egg

COUNTRY OF ORIGIN: United States

PARTS PREFERENCES: Not to sure, don't know too much about GPU.

OVERCLOCKING: Yes / No / Maybe SLI OR CROSSFIRE: Maybe not too sure how to use it.

MONITOR RESOLUTION: Using an old monitor that I am not sure what the specs are, will get a new one by january (what resolution do you recommend)

ADDITIONAL COMMENTS: I just want a good card that is compatible with the above mentioned materials, that isn't more expensive than $230. I wanted to know if I would see a big difference in gaming with a 560/650 ti instead of a 660. Thanks.