The only thing I would get different then what Dave told you is get an electric sheet metal cutter, not air. I had an air shear and it sucked. Went to home cheapo and got a Miluakee electric one, what a difference.
You may also want to get a shrinker/stretcher cause you will need to make bends and stuff.
But I do agree with Dave on the job you are tackling is not for a novice. Best bet is to at least have a buddy who has some knowledge in this area to be there to point you in the right direction.