If you have the budget I recommend using Jacquard Textile Color as your fabric paint with the Airfix agent mixed in as you go so you don't have to set your paint with an iron afterwards.
http://www.jacquardproducts.com/textile-color.html
http://www.jacquardproducts.com/airfix.html
Also another option is to get some friend make a duct tape dummy of yourself to slip the body suit over while painting.
http://latinvixen.phpwebhosting.com/dtd.htm