This has nothing to do with the Attract Mode theme (which looks cool) but your swappable control panels. I LOVE that idea. I wanted to do that for my Taito cabinet but abandoned the idea when I discovered that I'd have to rewire the coin mechs (I don't use buttons to replicate coin drops, only the real thing). However, seeing your rack of control panels makes me want to revisit the Molex idea where I wire a Ultimarc control board to a female end and then attach a male end to each of the control panels. Either that or do a smaller Molex for the coin mechs and then just mount a dedicated control board to each control panel and then go USB to the PC.
Which method do you use?
While i dont know why you would go with an ipac since its keyboardbased, when most people these days thanks to xpadder use joystick input boards that being said for connecting ALOT of controls like that id recommend one of the following
Make each panel terminate to a jamma harness that then connects to a male end that connects tot the ipac inside
or
Make each panel terminite to a IDE 40pin connector that then connects to a male IDE that inturn is wired to the ipac
Going molex route means you would have upwards of 10 connectors to connect/disconnect and that be a pain in the ass
For me Id go with usb based solution since you can get cheap usb encoders for 10bucks, id have one permanently inside the machine for coin test service then place 1 each per CPO so the only connect/disconnect when changing pannels would be a single usb cord