Behringer FCB1010 footswitch MIDI
One of the things that makes it so popular is that there are third-party upgrades available for it. You have to open the unit to replace a chip (EPROM) inside, (so kiss any warranty goodbye) but the chips are easy to replace - no de-soldering/re-soldering required, and they are relatively cheap. One of the most popular is the Uno chip, for about £25. It fixes some minor bugs in the original Behringer EPROM firmware and adds support for programming through a couple of PC/Mac based tools, rather than programming via sequences of button presses, which the original Behringer firmware requires.
I got mine to use with a Kemper Profiler and got it working straightaway. I've also ordered a Uno4Kemper dedicated EPROM that is pre-programmed to work with the Kemper (bacause I'm lazy). The FCB1010 is 1/4 the price of the offical Kemper remote, and has expression pedals toboot, so a good option.
(The only slight downside it it's pretty big - 70cm wide - but it has to be to fit all the controls on it!)