[miller]

Is there a point adding 100$ to the 750 to get 850 ? O___O

I'm not sure off the top of my head how much that graphics card draws (but I imagine it's a lot). Getting a higher wattage PSU would allow you to throw in a second GTX 580 in SLI whenever you wanted to. However, if you don't plan on doing this, stick with what you have.

750W is enough for the build that I posted. However, if I plan to overclock my comp, I will need a 800W supply.

Now, I am starting to think it's better to get 2x560 Ti cards for the same price as 580 GTX and throw in the third when its necessary.