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

Hopefully someone out there can help...

I would like to get another command station as a back-up in case mine breaks down before a gig. I have the xl-7 rom, mo-phatt rom and the beat garden rom in my xl-7 command station. I want to pick up the mp-7 or px-7 to use as a primary station with the one I have now as a back-up (I can't get past the ugly ass yellow!!) My question is; do I have to buy duplicate roms in order to properly transfer all the songs, presets, and patterns into the other command station, or can I get away with just the roms that I have and physically transfer those over?

Thanks,
attriphonic