Yamaha DTXpress/DTXplorer/DTXtreme

OK,  I've abandoned the canned music Idea, and just figured that I'll just 
wow the audience with effects...Good Plan I  think.  I have a question for 
anyone who can help.  Does anyone know where I can pick up the RS80 
Rack?  Just the rack?  maybe an online store or something ,  I can't seem 
to find it separately.  It looks a little more sturdy than the RS60 that 
the DTXPRESS came with, or better yet,  Does yamaha offer extender  bars or 
something to make it a bit bigger to fit more pads?  My plan is to build 
the ultimate E-drum kit,  I've had it with acoustics, to big bulky and 
heavy, Even a small four piece is a chore to get around, and it doesn't 
make all those cool effect noises that can really spice up a tune.  I so I 
need a bigger rack I'm looking into the DTX2 brain(don't get mad at me) and 
some more Dual zone pads.  any Ideas on the rack?

Herb