I ran one of those LL Adapters in mine and wasnt pleased with it. There was always background noise, and it kept resetting, mainly when there was a surge in the circuit from the Pepsi machine or the Washer/Dryer). It does have headers for fire buttons, so you can either add fire buttons to a new panel or tap into your start buttons.
I switched to a Jamma Boards adapter with a switcher and am happier with it. Just tap the switcher into a 120 source inside the cab (I tapped mine in near the AC Filter). Another advantage to that adapter is it has jumper settings, so your start buttons can also act as fire buttons without any wiring needed. Only con was I still had to tap in an extra ground wire (for whatever reason), but I like it. I can rin the 48-1 in my Ms. Pac-Man without any hacking needed, still using the original CP as well.