To keep that RAM you'll want to stay with socket 939. Best bets there are for the CPU choice to go with a dual-core Opteron 165 or 170. Motherboard choices, there are many if you want PCIe. DFI LanParty NF4 series is good from what I hear, and is what I've ordered to replace the lousy ASRock I was suckered into getting to start with. You'll need to decide if you want to ever do SLI or Crossfire. If you do, be sure to get a board that supports one of these (SLI for nVidia or CrossFire for ATI). If not, then you don't need to pay the extra for an SLI board. As far as the video - check out the buyer's guide at TomsHardware. For under $100 you can't beat the x800 series, slightly over it is hard to beat the x850 series. nVidia is only competitive, IMHO, when you start hitting the high-mid range cards and up.