I use a Badger 250-2 I bought from Amazon, with which I also purchased a half dozen extra jars. Today their price for both items is $27.85, plus shipping It is external mix and a simple as can be, but it does its job, is easy to clean, and a quick finger to direct air down the pick up tube clears clogs well. It has a pretty good spread and you can vary the width by how close you are to the work.
I picked this particular one on a recommendation from potter Martha Grover.
I also bought a set with with a sprayer and several quick change bottles from Harbor Freight. It is pretty cool to just unclip a bottle and change to the next to continue spraying and not lose the creative momentum removing, cleaning and installing a new bottle. It was $9.99 if I recall correctly.
I don't see spending a lot on an air brush that I am going to spray glazes through. TCP Global has a page with the Iwata Eclipse models here: