You linked the GPU twice. We don't know what PSU you have.
The GTX460 has a max TDP around 175W, you can expect closer to 150W while gaming. I like to use max figures so I'll stay with the 175W. We also need to know what CPU you have. Duals can run anywhere from 68W-100W, while quads can run 100W-125W.
If you use the 175W figure for your GPU, add another 100W for your CPU, and toss in another 50W or so for your mobo and drives, then you need around 325W for your system. This also needs to be available from your 12V rail. 325W / 12V = 27A. Any QUALITY PSU that can output 27A or more on the 12V rail should be fine to use.