Make-up artists like to use a gravity-fed dual-action airbrush with a 1/16-ounce medium sized cup on top. With make-up, you are not using a lot of material, so a medium cup is preferred over the larger 1/3-ounce cup.
Airbrush tanning is usually done with a single-action siphon-fed airbrush with a 3-ounce jar.