Buy a nice long arm kit. Forget about tryin gto make you own. If you have to ask how, you won't do it right, and everyone else on the highway mae be affected by your mistake.
I know, sounds harsh, but there are great kits out there that are all ready to be bolted on. Things that'll make that TJ go places that 95% hardest of ahrdcore rigs will go. For the other 5%, get a winch.
Sell the Vette motor, and get something with good low end torque, all that horsepower after 4,000 rpms aren't gonna do yu much good chugging along at 4mph on some trail.