.. the GTX 260 and GTS 450 are on par for performance.
That's not true. The 450 is behind the 5770 witch is just a little slower than the gtx260, but i suggest buying the gts450 because of DX11. Might want to find a 5770 for just a little over that price because the difference in performance will be worth it. If you want just nvidia get the gts450.