Building a new system to run Linux and virtualize XP

I am building a new machine to run Linux (Fedora 9 x86_64 bit) and virtualize XP Pro with vmware (some games) for less than $850. The following adds up to $670.

I pretty much spec out all other hardware but the motherboard to support 8GB memory later. Which motherboard do you guys recommend? The whole system needs to be 64 bit.

This must sound stupid, if the mobo supports DDR2 1200/1066 memory, does it mean it will support DDR2 800 memory too?

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SONY 18X DVD±R DVD Burner Black ATAPI/EIDE Model DRU180A - Retail
Item #: N82E16827131056
Seagate Barracuda 7200.10 ST3500630AS 500GB 7200 RPM SATA 3.0Gb/s Hard Drive - OEM
Item #: N82E16822148136
GIGABYTE GV-RX387512H Radeon HD 3870 512MB 256-bit GDDR3 PCI Express 2.0 x16 HDCP Ready CrossFire Supported Video Card - Retail
Item #: N82E16814125086
CORSAIR CMPSU-750TX 750W ATX12V / EPS12V Power Supply - Retail
Item #: N82E16817139006
A-DATA 4GB (2 x 2GB) 240-Pin DDR2 SDRAM DDR2 800 (PC2 6400) Dual Channel Kit Desktop Memory Model ADQVE1B16K - Retail
Item #: N82E16820211188
Intel Core 2 Quad Q6600 Kentsfield 2.4GHz LGA 775 Quad-Core Processor Model BX80562Q6600 - Retail
Item #: N82E16819115017

I think VMWare has suport for DX8 but I'm not sure. I might be thinking of something else.

The motherboard has 2 pci-e x16. and is crossfire compatible, decent overclocker, and has 16GB of ram support. It even has raid options all at about 150 which seems to be your price limit. The only thing is that in crossfire it will be 2x pci-e x8, but really that should bottleneck your graphics.