Do not buy any cooler master power supplies! so Easy choice therei s the XFX. If you go with a 5850 or 5870, 650watt will be fine. If you go wit hthe 5970... you should be buying an 800watt PSU.
5970 is overkill tho, get a 5850 and you'll be set. the 5870 and 5970 are really only utilized by the most hardcore gamers at the most insane resoulitions. For 1900x1080, 5850 will cruise through all your games on high settings.
^ Don't be too scared of CM PSUs. My friend has a CM Elite 400W and it's working perfectly, I've got a Silent Pro M850 and it's pretty good too. Regardless, between the two I'd get the XFX anyway because it would probably be better quality. With one HD 5850/5870 a 500W PSU is fine, two HD 5850s you'll need a 650W PSU, two HD 5870s a 750W (recommended) and a 700W at least for an HD 5970. (Really, they're underclocked HD 5870s so they'd use less power)
The processor is OK, the Phenom II X4 955 should be enough, and if you want to overclock you will want a better CPU cooler. The RAM you have chosen is fine.
As for your overclock, there's no need unless you need more power.
If you live in North America, XFX is the best choice, otherwise it doesn't really matter - the Vapor-X models from Sapphire are nice.
oh ok the question for the CPU is because i seen in the internet that there is 2 ver in the 965.. a 140w and a 125w and it says that the 965 125w was much more better than a 955... but ok ... i just want to overclock it if its necesary.. and isnt a good idea to pick up the amd phenom ii x6 1055t?