You could do the switching with a three button footswitch and several relays, but it is likely to get messy. I did some switching using relays on an amp I built and, while they work well, coming up with the scheme can be very challenging. Unless you are really good at thinking through signal switching paths, I would say "Just don't do it, man!" Of course, you can learn a lot by trying to do something that you don't know and that is difficult. Good luck.