i remember reading benchmarks for 4gb vs 8gb ram in heavy games, and the 8gb won by like 20%, and also not all 6950's can be unlocked, not a good thing to try if ur new to pcs let alone overclocking. and have a small amount of money to spend.Kabutos said:I would really wait until Sandy Bridge comes out before building; they're right around the corner.
However, I've seen some people in here recommending i7's and such. At the moment, you're not going to need more than an i5; if you have the money for it then go ahead, but in the interest of saving money I would stick to the i5 760 (and by extension, 4GB of RAM in dual channel).
EDIT: I should clarify: For gaming. an i5 and 4GB of RAM is all you'll need if you're only gaming. If you're doing something like heavy movie editing and 3D rendering and such, then you'd want the extra power.
With the saved money, I'd recommend getting a 6950 and then unlocking it into a 6970.
link to unlock:
http://www.techpowerup.com/articles/overclocking/vidcard/159