Advice needed for Computer Uprade! (To Vista, or not to Vista)

Well, for those of you who don't know, my last choice in purchasing a motherboard was a complete disaster.
I elected to get the evga Nvidia board with the 680i SLI capable chipset. It gave me four months of absolute hell- random crashes, BSODs, freezes, lockups, RAM timing issues, and it has now finally died alltogether.

That said, I am looking for a new, Non-SLI and non-EVGA Motherboard for a Socket T (The Core 2 Duo) Processor.
Anyone have any good suggestions for a stable Motherboard that is PCI-E capable, will support my
Corsair XMS2 DDR2 5400 RAM (Unless upgrading this is worthwhile? I'll be getting an additional 2 gigs if I am upgrading to Vista.)
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That said.. my next question is whether or not I should bother Upgrading to Vista, since I'll be doing a fresh install anyway. I don't mind purchasing the additional 2 gigs- my concern is with compatablity and stability at this point with other programs.

Is it worth buying Vista Ultimate and setting up a dual boot yet?