Try a search for "Vintage Air"
I was going to put a/c in my car and I know that this was the best fit and least noticable inside. Cost was less than $3,000 US.
I had a long thread on this topic going back in '02 in "All Cobra Talk" as I remeber. I bought a Cadillac EXT as daily driver instead, and I can tow the Cobra with it.
Good luck,
TL
