I use the "Single Mounted Heat Troller", I have it mounted in the extra switch plug on the left side of the ignition switch. The plug that I plug my jacket into comes out between the tank and seat. It works real well, there is an LED that flash's, faster for more heat, slower for less heat. I just need to find a nicer knob for it, I would like to find a smalller black knob.
http://www.warmnsafe.com/single-mounted-heat-troller/