i'm sure somebody knowledgable will help you out shortly, but afaik, since the 600 is a stripped down 1200, any old ide hard drive will do (laptop one would be nice and mini, but then you'd have to get a converter). 1gig sounds reasonable. you could definitely install os 3.1 or watever, for 3.9 i'm not sure...it comes on a cd so the contents are likely to be under 650mb so you'd still probably be fine
