"we want to make a controller the size of a coffee table with buttons as big as a hand and a joystick thats about 2 feet tall. I know this can be done, but I'm fishing for some ideas about how to construct the buttons and joystick." That shouldn't be a problem, you can make the controls as big as you like, its how they are connected to the cab. All joysticks/buttons in essence are just switches so as long as they contact when moved your fine. I once made a wireless guitar stomp box out of an old Logitech sidewinder joypad and used 'joy to key' and 'rejoice' to interface my midi signals, worked a treat.