I've got the old-style, strap-free, Throttle Rocker (which is still available from sources outside the US). I love mine! I've got a throttle lock too and if I had to give up one, it would be the throttle lock. A throttle lock doesn't do much for you unless you're riding on flat roads, so I get very little use out of mine. (I haven't used the lock once this year.)
There are electronic cruise controls for motorcycles and IIRC, there's even a website(s) devoted to adapting a universal automotive accessory cruise control to m/c use.
JMHO, but when it's time to put an electronic cruise control on my bike, it's time to get a bike that comes with one as factory equipment (ie Goldwing, BMW LT, etc.).