Looping effect combined with AEGP?

I am trying to make a plugin similar to the Checkout sample but where the footage continues to loop after it ends. So at this point, I am wondering if it's possible to do it just as an effect, or (most likely) I'd have to use AEGP.

I am also wondering how to find the layer ID which I would probably have to pass to AEGP to retrieve its length and whatnot (plugin selects a layer through a param and I need the ID of that layer).

And if I do have to use AEGP, what would be the process of implementation?