Vintage Air system?

I've owned my '70 coupe since 1977 and survived without air conditioning ever since. Now that I live in Hotlanta, and am a few years older, my heat tolerance has diminished to the point that I'm considering installing A/C in it. I'm looking at Vintage Air systems and I've found their prices, like everything else, have increased considerably. So, here's my question I hope you can help with... Can any Vette Registry members recommend good reliable sources of Vintage Air systems at reasonable prices? TIA.