urethane kit for a 93 teg

I've looked around and haven't been able to find any urethane body kits for my 93 teg. I owuld prefer urethane over fiberglass because i live in vermont and roads arn't very well kept here, and i don't want to be fixin a fiberglass kti from rocks every year. so if anyone knows of any sites that would sell a urethane kit for my car it'd be a lot of help.