Need Help.

Alright, I'm in the planning phase of constructing a frame jig for my two door garage, because chassis and suspension interest me more than actual bodywork, now here's my problem, I'm having troubles deciding on what metal to construct it out of, and what would be the best way to level the jig out, I don't want no half assed job, because i'll be driving the frame I build...as will friends, when they build theirs on it. All i need is some general help, and I'm sure I'll go from there..

For the legs, I was thinking that I'd make 8 Legs, atleast 4 feet tall, with some type of adjustment on the bottom to level the base out, like welding a nut inside the square tubing and use bolts welded something? i dunno, need ideas...

pretty much, starting from scratch on this project, and need alot of help..

Thanks,Chris