http://www.herculiner.com/
thats what im doing mine, well the bottom of the frame anyway.
if using rattle cans make sure its npt the cheap $0.98 walmart crap, spray it on heavy (without runs) and put a few coats on. get a few extra cans for when it chips or scratches. i did my 88 bronco II with rustoleum and it held up great in the trails, i mixed 1 part paint 2 part thinner IIRC and sprayd it on a little heavy, cant remember what kind of gun it was to spray tho