Well, after much debate I'm going with swappable metal panels on my old Frogger cab. The first one will be a single player CP with a 4/8 way joystick, 2 1/4" Happ trackball, and a TurboTwist spinner. The safe usable panel surface is 22" wide by 6.5" deep. The pic below is to scale. Your comments/thoughts are very much appreciated!
As for future panels, #2 will be a 2 player LS30 rotary panel, and #3 will be a 2 player, 8 way joystick panel.