Unless you have experience at welding, don't try it yourself. Unlike floor pans, the framerails must be precision installed. If they are off just a 1/4 inch, you could have some major alignment problems.
i am currently restoring a 240. probably wouldnt do it again but i just traded parts for this one and its definately worthy of restoring. besides i got the pick of the best parts out of 5 cars ive stripped and still have 2 complete cars worth of parts anyways if i were you i'd save up 5000 and goto cali arizona whatever. if you're just startin out in a z keep lookin find somethin decent. may end up being cheaper in the long run this way and less hassle to. rust is the only negative to a Z. do it right get a good one.