Midland 75-822 handheld CB is frequently mentioned. Connect to Sena SR10 two way radio adapter, has a push to talk on the device and a remote button that you can plug into device and put on left hand grip. The Midland radio comes with a car power/external antenna adapter or you can use batteries and the included rubber ducky antenna.
I have been looking at this for quite a while, there is a RAM mount for belt clip radio that can be used to hold the Midland CB on the clutch reservoir.
ram mount.jpg