Make sure on your new pc the drive is not sata native. ( long story )
I had vista and just had enough its fricking crap nice bells and whistles but just crap over all , maybe in a few years it will be ok but not now. And because my pc was designed for vista only getting xp on it was a nightmare, ( lucky for me I found a HP tech guy who was running same pc as me and had made most of the drives I needed)
IMHO get a custom pc made for you and get xp pro on it. From memory vista uses 300 mb of memory by its self.