mold and cast lure heads.

[madcaster]

I would like to try my hand at molding and casting my own lure heads.  I've read I should use RTV silicon for the mold, and not sure if Poly Resin is what I should use to cast.  I want something that is clear, but when dropped on the deck of a boat won't chip or crack.  What would work best?  Where can it be bought (preferably on-line), and will I need any other products (release?)?  All info is appreciated. Thanks