I use a Vista Cruise. Mounting required surgery, as it is not designed for our bike. I rarely use it,
but nice to have on open road to give hand a temporary rest.
I had the Throttle meister on my old ZRX 1100 and FJR1300. As noted above, it would require some handlebar modification as part of the TM actually FITS INSIDE the handlebar. It worked good, somewhat a PIA to get adjusted just right and somewhat ackward to turn on and off.
BrakeAway Motorcycle Cruise Control - Application Guide - NOT cheap, super slick, top of the line, works excellent (I've installed several on my customers bikes). Also disengauges if you touch the front brake lever or just touch the release button..
If your going to do a bunch of slab riding and have some extra money to burn, IMHO, go with the "Brakeaway" set up.