A buddy of mine and I have long been wanting to try our hand at the airbrush body paints. For dragon con he brought a bunch of it that he had researched and was dying to try. So we went to it. Check it out.
I believe we got all our makeup from www.fxsupply.com prices are reasonable and the paint goes pretty far. We used both the Mehron and fx's own brand.
Best advice, have both a single and dual action airbrush. The dual action is key, but sometimes you need a junky single action to push thicker, less friendly paints (for some reason the red seems to be cranky).
The paints are non-toxic, so there shouldn't be issues with breathing etc. But I would recommend a dust mask as I was picking colored boogers all day.
Other than that, its just something you have to dive in to head first and start playing to really get the idea.