You might want to read the following two tom's articles:http://www.tomshardware.com/reviews/game-performance-bottleneck,2737.htmlhttp://www.tomshardware.com/reviews/game-performance-bottleneck,2738.html
At 1920 resolution, a i5-750 with a mild overclock to 3.0 and a GTX480 would be a fine combination that would cost less than either of the two options you mentioned.
The x6 1090T is not a particularly good gaming cpu. It is better used for multi core enabled applications.
The 5970 is a great card, but it is expensive and probably more than you need.
The i7-950 and GTX470 will be good, and give you the option of sli later. But... it is more likely that a better/cheaper/video card will appear in a year or two and make such a sli ugrade a poor choice in the future.