Model Master makes paint in both acrylic and enamels. Both are sold in the same sized bottles. Care must be taken as they can be mixed up if you're not careful. The acrylics have a light blue band on the bottle going from memory.
I prefer to use MM enamels. Sadly they have discontinued a good portion of the colors. I typically use the Testor's thinner that is sold in the larger metal can. It has a red / white wrapper and can often be found at any hobby store.
I typically use MM enamel paint mixed at a 50 / 50 ratio for air brushing. Half paint, half thinner. It is sometimes reduced even further if I'm trying to spray it in a thin line or use it for mottling style camouflage as was used by the German Luftwaffe. I'll use less paint and more thinner for these applications.
As far as spraying pressure, here again it varies. I have had my best results using between 20 and 30 PSI. You can drop the pressure more if you are doing finer detail work. It will depend on your style, and the type of air brush you are using.
This is a ball park estimation. Your mileage may vary...
Hope this helps.
