Good comments from somebody-00 and banthracis ^.
Actually, a quality 650w psu is sufficient to run a GTX580. A stronger psu will not hurt, but is only necessary if you are preparing for sli and a second GTX570.
My short list of quality psu's would include Corsair, Antec, XFX, Seasonic, and PC P&C. Any will do.
I like the XFX 650w unit; modular too:http://www.newegg.com/Product/Product.aspx?Item=N82E16817207002
the GTX570 requirement is a 550w psu with 38a on the +12v rails.
While you can usually OC a standard card, EVGA is giving you a nice overclock that is guaranteed for not much of a price premium. I would get the superclocked version.