I've been using an EMU Planet Earth module and I also have an old Proteus 2500 hardware sequencer with a couple of other ROMS in it that I got for cheap 2nd hand. The 2500 has the 2000 sound palate inside along with sequencing capabilities (the front panel lights up like a Christmas tree). I haven't explored the percussion sounds in the Proteus much. What I've checked out so far didn't ring my bell. I think of the proteus as chiefly a keyboard module.
The Planet Earth is a wonderful tool, though many of its sounds seem kinda flat in comparison to what can be got nowadays in software. The Planet Earth has several GM drum kits inside it - four pretty vanilla ones, and a bunch of exotic ones (brazillian, salsa, etc) and a set of 20 "Earth" kits some of which are really choice for what I'm doing. I've just been using my Zendrum for a few weeks, but I'm increasingly convinced that while modules can do some good stuff, software is where its all headed, or where I'm headed anyway.
GM or no GM, it seems that these modules are laid out differently, perhaps not significantly in MIDI # mapping, but in other ways that are significant.
When I was waiting for my Zendrum to arrive I was asking about modules too (see other posts). I must say, I don't recall that anyone said they were using a Proteus for percussion on a Zendrum - and the other units you cited (the 2080 and the QSR) were not frequently mentioned. In fact, I don't believe I've ever heard of 'em. Seems like A LOT of people are using Alesis DM-5 and DM-Pros and TD(s) from Roland. You might want to check out some of the prior postings on this subject.
Great good luck.
Peace & harmony.