WaynePA,
The ZW-L essentially has 4 PowerMasters built into it already. You won't need external versions if you use the internal ones.
You're on a good path though. Newer PowerMasters, whether built-in or external, have special functions for PS-1, PS-2 and PS-3, like "Fast Horn" and "Fast Bell".
Look at the user's manual for your ZW-L. There's a section describing these functions, and several more listed there as well.
Mike