Realistically, I think you already have it.
A real wheel swap on the 1125 is less than 10 minutes even taking your time and safety wiring things, and if you go chain drive like the 1190 it's even faster. The Buell wheel system uses all captive spacers and a fixed axle -- it couldn't be easier! The chain kit is pretty straightforward, too.
Same for the front -- adjusting the fork height is 6 bolts, and there's already 1" of movement available on the 1125r, and I have no doubt the 1190 isn't much different.