Getting 8800gt this week hopefully but some help

Ok i should be getting an 8800gt 512 mb version when its out this week, however i dunno what else i'd have to upgrade to keep it from bottlenecking. My current rig is e6400 core 2duo (not oc'ed), 2 gigs corsair ddr2 pc6400, seagate barracuda 1000.10 perpendicular hd. Would i have to upgrade my cpu or maybe get 2 more gigs of ram? One more question is, can i get like another brand of ram like G.skill with ddr2 pc6400 and combine with my corsair? Or must i get the corsair again to match with. Thanks.

You can mix & match ram DDR2 sticks, but it's BEST to use the same make & model to save your headache in the event that they don't like each other. If it's out of stock, you can get another kit that has the same specs.