Is there a product available that is pre-gelatinized starch and what product name is it sold with?
Yeah, what you want is UltraTex-3 (or possibly the 8 or UltraSperse variants), from National Starch. Willpowder carries them: http://www.willpowder.net/tapioca.html

You can make something very much like instant pudding from just about any liquid using this stuff, and it can be cold. No heating required. Works best with a stick blender.