You can't go by brand alone unless you tell us which model/size you are looking at. For instance, I import some compressor from Europe and while the line is broad and priced right, there are three or four models that just wouldn't work for you. I am sure that Airtex has the same thing going on.
You need to decide how much time per day you can spend filling tanks. You also need to know what kind of driver you need (single phase, three phase, gas or diesel). Set your compressor size according to those restrictions. For instance, to fill 20 tanks within three hours will require an 8 or 9 SCFM machine.
Additionally, you are going to need to add a separate filtration system. Most compact compressors come with a standard filter that processes about 3000-4000 cubic feet of air per cartridge. For your use, that means changing filters every other day! If AirTex, or any other supplier for that matter, doesn't tell you about the limitations of their compressor system, then just walk away.
And, as far as service is concerned, every manufacturer of compressor has spare parts available. However, it is your compressor mechanic that is going to have to be taking care of your investment. Any warranty will require that you bring/send your machine in, along with it's run time/service log, for any warranty work. In most cases, that is cost prohibitive, so it behooves your mechanic to keep it cool, clean and maintained to avoid any problems.
