You are in for a big suprise if you think the cheap airbrushes will do want you want.

Well I will give you some info to get you started.

You can get a Testors kit from walmart for around $30 or $40. They run off the compressed cans of air which are fairly cheap but they go fast so grab a couple. I think the kit actually comes with a small can. Keep in mind with the cans that as you pull air they get cold which causes a slow air feed. You will want to get a bowl of luke warm water and sit the can in it. Just so the bottom of the can is in the water. Will feed better.

The best thing to spray for bodies is pactra paint (IMHO), so you will need to purchase the small jars for use with the gun. You will also need lacquer thinner. Dont get a small jar, you will need to go to home depot and get a can of it. Basically you will have to mix and thin the paint with the lacquer depending on the effect you want. Each time you change a color you will want to shoot some clean lacquer through the gun which is most efficient. You can shoot the next color but you will have to shoot a bit of paint to clean out the gun. I would rather use thinner and save the paint.

Thats the basics of it, you will find that the cheap gun in the kit does not give you much control over the paint, you can get the same effect with the regular spray can if you want to know the truth. The cheap gun basically just gives you the option to mix the paint.

If you really want to learn to use the airbrush you might want to take a class and then get ready to invest a little cash. You would want a decent small air compressor and a good spray gun which would allow you to control the flow of air and the amount of paint.
Dual action gun.
They are not cheap.

As for the bodies you want to paint the inside only This keeps the paint from chipping off and such, if you use HPI bodies (The best IMHO) they have a thin plastic covering the outside which protects from overspray etc.

I also always suggest using pactra paints for bodies, it is a lacquer based paint which actually bonds itself to the plastic.

THere are other products on the market but I think Pactra is the most durable for the application.

Good luck with your airbrushing

Dbow