I was using 6.5+ on Vista, but am experimenting with XP currently. Note that Vista itself uses something like twice the memory that XP does. Some of that is for program preloading, and will be freed up if requested (although this introduces lag). Usually the first 512MB / 1GB goes to XP / Vista, or something like that.

Just the loading screens for 5 clients in XP hits 1.5GB, so...I wouldn't take that advice too seriously. It might be acceptable under XP for only 3 clients, but it will screw you over if you try that little RAM in Vista for 5.

But anyway...if you're getting 8GB, you should be fine with ANY version of Vista besides starter, and the stuff you were looking at already was the 1066.

Oh and BTW, I haven't had any driver issues on XP 64. Or Vista 64. There used to be plenty of issues, but mostly not anymore. Maybe if you're choosing really obscure and badly supported hardware?