I am still in the process of building this pc. So far I have a Sigma Monster 750w power supply. I plan on having either a Phenom ii X4 or X6 cpu. Haven't decided on a motherboard yet but leaning towards Crosshair Formula IV.
With that power supply, you can basically get any graphics card you want. Any budget?
Also, just to let you know, the new intel processors are now being sold. They blow the amd and even the old intels out the water without any real competition. Might want to consider them if you have no reason for going AMD. the i5 2500k is a great processor, probably one of the best intel has released in a very long time for its price point of only $225.