Which airbrush depends on the type of painting you intend to do. An airbrush typically puts out a spray pattern about as big as a quarter. Considering you will want to overlap a bit you can see why an airbrush may not be the tool to use if you are painting a large area. You will have to make many passes to cover a 1 sq ft area. Airbrushes are best suited for painting small models or trim/touch up on large models.

Single action airbrushes are MUCH easier to use, keep clean and maintain. It will take you a LOT of practice to get to the point where you are comfortable with the flexibility of a dual action airbrush.

I started with a dual action airbrush and it was a big mistake. Too many variables for a novice! Air pressure, thinning the paint, moisture traps, and atmospheric conditions to name a few, add the extra complexity of a dual action brush and you have a recipe for frustration. And what a pain to take apart and clean! Lots of little parts!!!

After struggling with a dual action for a year or more I purchased a single action airbrush and after using it one time I literally threw the dual action brush in the trash. The single action brush was dead simple to operate and maintain. I was able to get great results the first time.

Unless you really NEED a dual action brush, I suggest you start with a single action and learn to master it before moving on to the dual action brush.