Blasko1223: Thanks everyone for all the help. If I got a Corsair 650 watt psu, would that be fine for the 6950? Also, would it be worth it to get the 2gb version just to be more future proof? I don't plan on converting the 6950 to a 6970 since this is my first build.
prehto81: I have a Corsair 650W PSU (HX650W) and it's extremely well built and quiet too. I bought it for 110 euros a few weeks back (I live in Finland) and I bet it's mighty fine and enough for 6950. I'd need to know your exact build before I could say that for sure tho...
I have a Corsair HX620W, with my build..I have had no issues with the PSU.
Have used 2xATI 4850's in Crossfire and a single 5850 card too(before I got my 6950), no issues with the cards I have used with Corsair.
A 2GB 6950 card is a better buy, than 1 GB versions.
But...If you are incase going for a 1GB card, then you might also get a Nvidia 560Ti (factory over-clocked) card instead of a 1GB 6950. The Nvidia card is smaller in size and some Nvidia partnered games run fast with heavy tessellation.
Also before the buy, I wanna note that ATI/AMD drivers always has some problems..I don't know how Nvidia Drivers are!.. (@Prehto8; how are Nvidia Drivers?)