Emu XL-7 & MP-7 User's Group

I am checking out the mp-7. I have no clue how to build up my own 
custom drum kit like -lets say - a GM drum set. I´ve got a few 
midifiles with GM map that were nicely recorded, with fill ins and 
brekas and variations and I want to play them on the mp-7.

Another question: I found some overwhelming drum and percussion 
sounds on the mp-7, but most of the other sounds are just not usable 
because of their structure - they are more like hitsamples but you 
cant use this for proper melodies. Do you think the ZR Expansion 
boarfd or the protozoa would fit the bill for well sampled natural 
sounds?
Or do I have to switch to the RS7000???

Any comments?

Cheers

HEinrich