Sooner or later if you continue to search the net, what your looking for will turn up .
Might mean buying one with a 350 if the car is real clean and the floors look like the topside.
Theres a lot of perfformace advantages to buying a modified car especially if the front end has been changed to TCI or Heidts.
Pro-touring cars as they call them. But the LS series motor and all the good stuff takes the car into the $50G range.