Hi Phil, and welcome! I'm relatively new to airbrushing myself, and while I started off using an old Testors airbrush I don't think they make anymore, I ended up going with a Badger SOTAR 20/20, which works like a dream. I run it using a smallish air compressor (smallish for the pneumatic tools I originally bought it for, but large compared to the airbrush compressors). It has an air tank, which helps get consistency of airflow. I also bought a regulator with a moisture trap to keep water out of the 10-foot air hose with quick-disconnect fittings that make everything easy. You definitely need the moisture trap, as water in the paint system is bad news.
Others will have way better advice to offer than me, but here are a few things that I wish I'd been able to find right off the bat:
- Don't thin water-based (acrylic) paints with water. I tried that with Tamiya acrylics, and they sprayed awfully. Use a thinner (I use Tamiya's acrylic paint thinner, which is an alcohol base with a retarder in it that delays paint drying time so it doesn't dry before hitting the model's surface - which creates a dusty/gritty texture).
-I read a hundred times to thin something to the consistency of skim milk. That's great, but it was hard for me to get that consistency at first. Then I saw the recommendation of thinning with 2 parts thinner to 1 part paint (for the Tamiya products I mentioned above).
-PSI. People don't seem to like to talk about the pressure they're running. I have found that 18 PSI works great with the Tamiya paints thinned as stated above. If the paint sounds like it's sputtering or spitting, I add thinner and sometimes air pressure.
-I bought 100 eyedroppers from TCP Global for something like $15 to transfer paints. That makes them disposable, so I don't feel bad about not cleaning the ones I use with enamels and lacquers. They're really great for transferring paint and thinner to the airbrush.
Those are the things I wish people had told me right away. I've just finished my first model that I've fully airbrushed, and I am absolutely hooked. The color depth and evenness of the coating of the pain really have me sold on airbrushing everything - even things like aircraft cockpits that are easy to brush by hand.
Good luck selecting your airbrush, and be sure to show us the pics of your first model!
-BD-