New system component help

Hi all, I'm in the process of building a new system from the ground up. I'll be using a couple of SATA drives I already have plus my EVGA 7950GT-KO until the dust settles (if ever) on DX-10 and Vista and also be using WinXP Pro 32 bit. I have these components on hand: Lian Li PC 65B Case Corsair HX Series CMPSU-620HX 620W Power Supply PLEXTOR PX-810SA/SW-BL DVD/CD drive I am seriously looking at the Gigabyte boards with the P35 chipset but am unsure about getting one that supports DDR-3 as well as DDR-2 as DDR-3 probably won't be affordable for a year or two. The P35 chipsets will support the 45nm processors and Quads as well. As I am awaiting the upcoming price drops from Intel I am again unsure what processor to pursue. Am currently looking at the E6850 or E6600. I have no need for SLI. If any of you have recently or are in the process of building your input would be appreciated. Thanks, Craig