I have a dilemma, I can either have 4 gbs of ram (2 1gbs Corsair 1066 DDR3 and 2 1 gb OCZ 2000 DDR3) or I can just use the OCZ and achieve 2000 mhz. My question is, will the 2gbs be enough for Vista and Crysis, and all the other high powered games?

I would also like some help OC my computer if someone can give me some suggestsion.
I'm running an EVGA 790i Ultra SLI board, with an Intel Quad Core Q6600 at 2.4 ghz , with liquid cool and 850w of power.

I've tried setting the fsb at 1600 and left the cpu voltages at auto and turned on EPP 2.0 with just the 2 sticks of OCZ installed in slots 2 and 4. (EPP won't work for 1 and 3 for those of you who's wondering) However, I can only get past the Bios stage and afterwords am stuck with a black screen. I'm not looking to OC to 4 ghz or anything but I would like a 3.6 or 3.4 OC. I forgot my ram's voltage timings do I didn't change those, so if anyone could provide me with some advice I'd appreciate it. Thanks!

I would suggest 4 GB of RAM. 2 GB is just fair for graphic and desktop publishing.
You will need an awesome video card.

2GB is enough for vista and crysis, remember that it's DDR3, costs a lot more than DDR2, you will need a lot of money to get 4GB DDR3.

OCZ Platinum 4GB DDR2 SDRAM DDR2 1066 - $109.99
OCZ Platinum 2GB DDR3 SDRAM DDR3 2000 - $239.99
OCZ Platinum 4GB DDR3 SDRAM DDR3 2000 - $409.99