Go with Win2k.

It's got the same stability as XP (plus it's much more tweakable), without the IMO horrible GUI (I've been using XP at work, and have hated every second of it - yesterday I reformatted and installed 2k instead) and all the rest of the cruft (including "product activation" - argh!)

It costs more than XP home, but less than XP pro in the UK at least.

Win2k will be the last M$ OS I ever buy.