It sounds like functions are the right way to go. Create a function for each template, and call one whenever it's needed. For example, create 3 functions, each with a different template, and name them:
Whenever the played reaches the point that new level elements need to be drawn, use the action:
This will call one of the 3 templates at random. You could also do something more dynamic, and add little variation to each template so the player doesn't recognize the pattern. You could go even more dynamic by using a single function, spawn all the objects, and randomly set their properties from a set of values. Of course, this may not be practical depending on your game play. Regardless, I think functions are what you're looking for.