NOOB - 2-player + DOT stick/spinner questions!

[brimys]

Hi folks -

Noobie first build of a MAME cabinet here! Have been doing a ton of reading, but wanted to do a sanity check on the plan before I bought/built!

Looking to make a 2-player setup, with an auxiliary trigger stick/high-low spinner for DIscs of Tron.

Was planning on using the Ultimarc Ultimate I/O as the board, to handle the following:
 - Joystick_1 (P1)
 - 6 LED buttons (P1)
 - Coin (P1) - using physical coin door mech
 - P1_Start (P1)

 - Joystick_2 (P2)
 - 6 LED buttons (P2)
 - Coin (P2) - using physical coin door mech
 - P2_Start (P2)

 - Mini-Grip Trigger Stick (P1_aux)
 --> Trigger_button (P1_aux)
 --> Thumb_button (P1_aux)

 - Turbo_Twist_H/L (P1_aux) - I understand this has its own small board, so won’t be connected to the IPAC.

I’d love any help or thoughts on this, THANK YOU! A few questions:

 - Is this the best IPAC board for this?

 - When hooking in the aux. Trigger Stick, should I connect that to where P3 is on that board, or doesn’t it matter?

 - Has anyone actually wired up the Trigger Stick? Can you share pics of your wiring? I’m not sure where/how to connect the Trigger and Thumb button wires… they can go anywhere? Three wires coming out of this - two hot and a ground - so do I need to daisy-chain then, or simply having the one ground wire is OK?

Thanks!