Mark,
My old compressor gave out a year ago or so, and I decided look online for a decent "airbrush" compressor that would also give me a little more air volume than "airbrush only" compressors that airbrush companies sell.
After reading the reviews and seeing the comparisons, I decided on the Harbor Freight Tools Fortress 2 Gallon, 135 PSI, Two Connector, Aluminum Tank (no rust), 2.1 SCFM (@ 90 PSI) Ultra-Quiet (60 dBA) Compressor for $189.99.
I also considered their 1 Gallon Fortress, Ultra-Quiet (57 dBA) Compressor, but I decided that for the extra 30 bucks, a bigger tank, more than twice the airflow, two connectors, and only 2 dBA noisier, the 2 Gallon was the one I'd get.
However, for airbrush ONLY, the 1 Gallon model would work just fine I'm sure and be 2 dBA quieter.
Here's mine at work next to my spray booth.
I am totally happy with this compressor and I barely hear it come on. It pumps up fast and is excellent quality construction and provides plenty of air for a few things other than airbrushing.
Cheerio!
Bob Gilmore