That's too complicated. If people want that as prizes the best way would be to give "Free head tokens" or "Free body tokens" which would just be a small coin that would go in your inventory that's untradable and undroppable. It would just allow one free upload of any head or body of your choosing (depending which token it is to determine if you get a head or body). It would be rather simple, when you upload the body and get the confirmation it would give you two payment methods. The gralats, or the custom token. This would be much simpler and would require admins to do no work. But this won't happen anyway so the best prizes for admin hosted events that aren't at the event house like hide n seek would be hats. Ec works too.