Hello every, I am in the process of restoring my 65 4-door and I would like to add the factory option of air conditioning to it, since it can get really hot and humid here in PA! I have searched lots of flea markets and swap meets for the a/c unit, but I have not been able to find one. Will this process be expensive?? Are the factory units hard to install?? Where can I find one of these factory a/c units???