I'm getting back into building after a long time and would like some suggestions as to a good double-action airbrush ... thanks!

I've been using an AZTEC A430 for a while now and It's worked great. It's an external mix double action airbrush. I like the fact that with the interchangeable nozzles it's very easy to clean and the paint cups can be loaded on either side and being a lefty, that makes it easy for me to use. I paid @ $80.00 for mine. It also gives you the option of using either the Propel (canned air), or an air compressor. I hope this helps.

Can pick up an Iwata Revolution CR kit for likely less than $70.

Gravity feed, dual action