Check out the MeloAudio Midi Commander. I don't have one myself, but the idea appeals to me . It is smaller and simpler than some of the others (quite inexpensive too). I understand that it comes preprogrammed for Kemper so it is supposed to work right out of the box with minimal set-up time. I believe this comes with some limitations on functionality, so may or may not meet you needs. It does not have an expression pedal, but does have a jack so you can use your own. This is an advantage for some folks who have a particular expression pedal they like, rather than being stuck with what is built into the for controller.