Time for Vista/DX10!, but Which one?

OK,

It seems that I am about to get back into the world of IT support, after about 18 months in WAN/Telecom.
so now I will have to teach myself yet another OS - (gasp) Vista!?!?!

I have a spare hard drive laying around, so now we get to the question: Which version do I get?
32 or 64 bit? full or upgrade versions? Do I upgrade a windows XP drive or do a clean install?
Then onto the version I need to select: home, premuim, ultimate?

I will install this on an 80gb drive in the machine from my sig.

This will be a training / learning tool but since it will be on my main machine I will be looking for good hardware/ SLI / game support.

O and can you have a vista drive and an XP drive in the same box?

Thanks, Ed




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Member: SLI-22234 ewilson248
CPU: AMD Athlon 64 x2 5200+ OC (239x13=3107)
Memory: 2048
Motherboard: Foxconn C51XEM2AA 590 SLI
Graphics Cards Manufacturer: BFG
Dual NVIDIA GPUs: GeForce 8800GT OC + GeForce 8800GT OC
Sound: Realtek HD mobo audio
Hard Drive(s): Seagate SATA
Benchmarks: 3DMark06 - 12,328 3DMark03 - 58,725
Notes: Viewsonic VX922, Logitech THX SS, Logitech MX610 lefty laser, Antec nine hundred case, Antec 650 tri-power PS, Zalman 9700 cooler.

Uh, tech support?