Roland System 100m

Excuse my ignorance on this (musician rather than technician) but maybe someone can 
clear this up for me.

I currently have a UK 'basic' 5 module unit but am looking to expand. Now, I know that I 
could maybe get a Japanese or USA version 5 module unit and then use a step down 
transformer if it was 100V or 110V or whatever. But how about individual modules? eg. If I 
had a UK 191j rack, could I buy a Japanese or US individual module and fit it straight into 
the UK rack? Or is the type of power supply specific to the individual modules?

Hope that makes sense! I'm sure some of you know what I mean and can give me some 
advice on this.

By the way, I'm keen to get hold of the sequencer module(182) in particular but they seem 
to be as rare as hen's teeth. Don't suppose anyone is looking to off load one? Cash not a 
problem.

Cheers