How Do I Find New Object Types for C2?

I have been looking around on the site but don't know where I can find downloadable Object Types for use in games.

They are called plugins or behaviors.

Here's a list of all of them

scirra.com/forum/topic47002.html

I ask this because I am trying to add an AUDIO object to my game, but I only see VIDEO object and USERMEDIA object as options.