You are to be commended for wanting information on Cosmetic grade body paint. This shows respect for your model. (Non-Toxic Craft Products are NOT Makeup.)
A good over view of what brands and products are used by face and body painters is www.sillyfarm.com
IMO - I would NOT advise Liquid Latex as a newbie body paint. It doesn't offer the line control of traditional water activated body paints like WolfeFX. Let alone latex's safety, allergy and technical considerations.
Take a walk through the FAQ - the is TONS of reading on the subject of body paint products, application, safety.....