My first question is what is better for my (dimension e510)'s 8800 GT OC and pentium 4 3.0 ghz processer a dell silencer 470 or CORSAIR CMPSU-450VX ATX12V V2.2 450W Power Supply 90 - 264 V UL, CUL, CE, CB, FCC Class B, TUV, CCC, C-tick or Enhance ENP-5150GH 500W ATX12V Rev.2.2 (24/20+8/4+6), 80+ RoHS, Quiet PSU and, will all of these be able to adequately run my pc? Im already not thrilled at buying a new psu for my comp, but mine is only 305W so it is necessary. I want to spend as little money as possible, while still being able to have a proper psu. Next is a question about upgrading my memory. I plan on playing games such as cod4, bioshock, oblivion, lost planet so what type of memory and how much should i get. I have a dual 512MB channel already, but i have no idea what that means or how that will affect my decision in choosing my new memory. Some questions I have is, do I have to buy the same type of memory I have in my comp currently?, How much memory will allow me to adequately run these games?, and do I have to to strategically place new memory in my motheroard(for example if I wanted 4 gigs of memory, do i need to buy 2 more 512Mb dual channels and then buy 2 more dual 1 gig channels)?