i've made a styrofoam mock-up:

feels very comfortable and confirmed all the conclusions on my web page:
click HERE.
i think all i need to decide are:
(1) which joystick model to use for the front-and-center 4-way (leaning toward the Ultimarc J-stik or possibly the Mag-stik). not considering ms pac reunion, since it's not a SlikStik standard option.
(2) whether to choose the SlikStik flight stick (is it the Happ "Heavy Duty 8-way Trigger Joystick"?) or the SlikStik (Happ) Top Fire for Discs of Tron. i'm leaning toward the flight stick. after quite a bit of web searching, i haven't found a single instance of a user reporting how the SlikStik flight stik option works for Discs of Tron. if anyone out there can comment, please do.
(3) which joystick model to choose for the Q-bert stick (leaning toward the Ultimarc J-stik).
if anyone has any opinions about the various joystick choices, please let me know.