A decent mid priced system

This is what I chose so far:

Motherboard: MSI B75A-G43 Socket 1155
CPU: Intel Core i5-3470 IvyBridge 3.2 GHz Socket 1155 box
Memory: 2x4GB 1600MHz DDR3 CL9 XMS3 Heat Spreader
Storage: SSD Intel 330 Series 120GB SATA3 MLC + HDD WD Caviar Blue 1TB SATA3 64MB 7200RPM
Power: OCZ ZS Series 550W
Case: Aerocool Strike-X GT Black

Now the issue is with the video card:
Gigabyte Radeon HD7870 2GB DDR5 256bit vs Gigabyte Radeon HD7950 WindForce 3X 3GB DDR5 384-bit vs Gigabyte GeForce GTX 660 Ti WindForce 2X 2GB DDR5 192-bit.

In my list of preferences would be 7950>7870>660 Ti.

I am looking for advice concerning what would fit best with the rest of the components ( manking the most out of the video card's potential, don't see the point in buying an expensive card if the rest of the system can't use it at it's full potential ).

Notes:
- Didn't post any links with the products since they will be bought from a local distributor.
- To have a good orientation on the general pricing around here the above system including the 7870 card is worth around 1335$ with taxes ( 1077$ without taxes) - prices in Romania.
- Tried to look around the builds in the http://www.tomshardware.co.uk/forum/370751-13-bestconfi..., looks appealing but with the currency conversion there isn't much difference.