I know this is an old post but I just stumbled upon it.
Another thing that may help you to know is that ANY midi-capable device can be a sound module for your Zendrum... a midi keyboard, drum machine, sampler, etc. My first Zendrum module was an Alesis QSR keyboard sound module, and the drum sounds weren't half bad.
If you are planning to use the Zendrum for drum sounds, as most do, check whatever gear you may want to try as a module to see if it does indeed have drum kits... my Kurzweil electric piano, for instance, does not.
And, I love your username!