i'd be interested in this also. I fabbed up a prototype 2-1 for my SM that worked ok. need a custom mid-pipe for it though and the Yosh can i used was too loud for my.
the extra tank capacity would be great though if it is realistically priced. One tank design could work for SE ADV and SM with bracketry for each if necessary.
really good idea though. keep us posted
"I only wish I had video running when WSD did a no footed can-can over some boulders on mainline....two feet of air easy..." -Abdelhub
Yeah, on the GS http://vimeo.com/3232838
Notable Past-'01 KLR 250, 95 R1100GS, 06 KTM 950 SM, 69 Bridgestone 90