Im wondering if this CPU (3Ghz x4) will bottleneck my performance with the GTX 460 768MB, and If i will se an Improvement in FPS or in general if I upgrade t the Phenom II 955 (3.2Ghz x4 with L3 Cache).
I don't know if that is a wise choice. 550ti should be cool if you really like overclocking, but I wouldn't suggest it otherwise. I'd get a hd 6850, but I know it is a little higher priced than you want. What're you running now?