What Control Interface for an Arcade Table with 2 Trackballs?

[Ellegon]

Hi all,

I'm a bit overwhelmed and my searches didn't help me. So here's my humble request for some input/help :)

Background: I'm planning on building an Arcade Table. 2 Players can sit opposite of each other to game. I'm planning on using a Pi 3 (or Pi 4 if needed) and would build it out of an existing table.
Now I did build a retropie with two arcade controllers (10 buttons and joystick) using an SJ@JX controller interface. That worked more or less, although the configuration was not easy and I was never really satisfied.

This time I did a lot more research and want to go with IPAC (most likely) as it seems it's easier to get a good setup (found an amazing tutorial for it). However, if I want to have two trackballs included, what CI would I need? The IPAC2 has only one connector for a trackball (it seems) because normally you can share it. And on the IPAC4 I don't see a trackball connector at all? Would I need to use two IPAC2's? But how would I configure them? Player1 on one IPAC and Player2 on the other one? But what about the Trackball?

It's all very confusing atm. I also noticed that my old joysticks use a flat cable with 5 wires to connect to my SJ@JX CI, but I guess I could rewire them to the single pins on an IPAC?

Does anyone maybe know a good tutorial on the Controlling Interface for Arcade Tables?

Any help is appreciated...