Ktm sxc 625 - 6th gear, SM wheels, exhaust ?

[Kris Zimmermann Nielsen]

hello guys !

 

i have a 2003 sxc 625 i want to convert to supermoto, and i have found at set og used wheels, but the guy says the back wheel is 5" wide, is that too wide og is it possible to fit my bike ? also is it possible to fit a 6th gear in the 5th gear lc4 motor like mine ? and where do i get a full titanium exhaust like akrapovic for the bike ?