To the OP: perhaps an alternative is a tank system instead of a compressor?
I recently moved to CO2 , and find it very conducive to painting. Quiet, fast, easy and VERY adjustable for pressure settings. I moved from a single stage piston compressor with no regulator so I'm loving the change. I had an advantage tho, I already had all of the expensive stuff (tank & regulator) from my beer brewing hobby.
As to adaptors, I took my airbrush and beer tank hoses to the big box hardware store and played withthe fiddly bits until I got something that worked. As I recall, I did end up standing in the dispensing aisle of the beer brewing supplies store for a bit as well.
Ultimately I want to get a multiple tap distribution valve so that I can have multiple airbrushes hooked up at once. Unfortunatley Ive got different terminal connections on my two existing brushes.
Don: if you can get to 100 and Excelsior in St Louis Park with 30 minutes to spare, check out Midwest Brewing, they will have everything you need. I'd guess about $ 150 for your tank, regulator and assorted adaptors.