There is going to be a lot of fiberglass and lexan in your future. I would also look at lightening the front K member a bit and aluminum heads. That is where the biggest part of weight savings are going to come from. I (on a car I used to have) cut out all the excess metal below the 1/4 window and rear seat v bracing. A fuel cell will help some. get rid of factory wiring and put in what is needed as far as a switch panel set up. The one I did the factory harness compared to a Painless 50005 I lost 10 lbs from getting rid of all the junk. Every little bit you can trim will make a difference. Going to a tube chassis set up will be the best way to get the weight down. But I don't know what your budget is or how soon you want to get it done.