Sifen Yamishi
Borrowing this tip from a friend of a friend:
Do the body paint like so, then cover yourself in baby powder. The pain should stick to it, but you won't have pain smearing all over people, etc.
This works, but make sure you're careful until the paint and powder set. You can also use Ben Nye's make up sealant (it works WONDERS!!!)
In terms of the paint itself, my friend and I have experimented with both oil and water based paint. You can more easily get a even look by using water based paint, and it is a lot easier to get off when you're done. That being said, I've used combinations of oil and water based paints for differing texturing effects.
I've been pretty happy with Ben Nye products in general, but have also used Kryolan for different color options. I've heard some good things about Diamond FX, but haven't experimented with it myself. If you dip into theater body paint, know that it will be A LOT thicker than general body paint. It is designed for an audience to see from a distance, but is more heat and sweat resistant. That being said, sealants like those from Ben Nye can help make recreational body paint more sweat resistant, which is why I've switch to the sealants from baby powder.
If you haven't really used these products before, test them on your forearm first before applying a full-body application. It's better to discover that you're sensitive to a product on a small bit of skin than your whole torso.