I have found that my kids can come up with issue play of equal quality to anything I can buy.  As long as they can keep to a simple theme, and keep their audience in focus, they usually delightfully surprise me.  Often they go with a "Game Theme"  where they have a character play a game and watch little scenes where the action is stopped and they character must make a choice of what to do.  Very simple, very obvious choices with that young of an age group.

Plus, since they come up with the script, it is easier to memorize!