Requirements:
- Goal is a high end gaming rig
- 8GB RAM on Vista ultimate 64bit (to turn page file off and go pure RAM)
- Lots of 3D gaming - like to switch out of game into forums, and run stuff in the background
- Plan on an intel quad core CPU
- Plan on dual SLi cards
- Plan on water cooling - considering the H20-220 Apex Ultra
- Budget for the MoBo: Not the issue

Questions:
- Recommendations?
- If the MoBo is DDR3 does that mean I can or cannot use DDR2 RAM? I was wondering if it's possible to buy DDR2 now and upgrade to DDR3 later.

DDR3 and ddr2 aren't interchangable in the same slot. A few boards have 2 slots of each. Current cpu designs don't take advantage of ddr3 performance; if you want the latest and greatest, I wouldn't spend too much now. I'd wait for the nehalem core to come out in 6-12 months. The asus maximus series are beautiful boards, but I got rid of mine, as it was ddr3 only. I didn't want to spend the extra money after reading some reviews.

Pioneer 20X DVD±R DVD Burner Black IDE Model DVR-115DBK - OEM
$32.99

Antec Nine Hundred Black Steel ATX Mid Tower Computer Case - Retail
$109.99

Western Digital VelociRaptor WD3000GLFS 300GB 10000 RPM SATA 3.0Gb/s Hard Drive - OEM
$299.99

(2) EVGA 512-P3-N871-AR GeForce 9800 GTX(G92) 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready SLI Supported Video Card - Retail
$539.98
$269.99 each

Thermaltake Toughpower W0132RU 1000W ATX12V / EPS12V Power Supply - Retail
$329.99

2xG.SKILL 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model F2-6400CL5D-4GBPQ - Retail
$84.99x2

XFX MB-N780-ISH9 LGA 775 NVIDIA nForce 780i SLI Intel Motherboard - Retail
$259.99

Intel Core 2 Quad Q9450 Yorkfield 2.66GHz LGA 775 95W Quad-Core Processor Model BX80569Q9450 - Retail
$339.99

Microsoft Windows Vista 64-Bit Ultimate for System Builders Single Pack DVD - OEM
$169.99

ARCTIC COOLING Freezer 7 Pro 92mm CPU Cooler - Retail
$26.99

Subtotal: $2,279.88