The TC Electronics RH 450/750 has three preset channels. I have a 450 and use one channel set up for each of bass; one passive, one active and keep the third free for anything else I might need to do - extra overdrive, compression or perhaps eq'd for a specific effect, etc. But in your case one for each bass would work perfectly and with the foot controller, it's easily switchable and you get a nice tuner as well. Simplez.