Amen Howard.
I’d say maybe add the trackball. Unless your all time favorite game is arkanoid or tempest, lose the spinner. I’ve built 4 player aircraft carrier panels, 2 players with trackball, spinner, and dedicated 4- way, and a 2 player panel with 2 ServoStiks and a trackball.
I used the exact same controls 99.9999999999% of the time ON ALL 3 CABINETS. It adds work, another think to troubleshoot, and while most people don’t listen to this advice, I’ve had many people tell me they should have listened after the fact.
Go with ServoStiks though. There is a servo that automatically switches you controllers from 4 to 8 way mode based on the game you’re launching. They kill the need for a dedicated 4-way stick and are amazing.
For an interface, go with an Ultimarc iPac 2. Hands down, no question.