All you would need is a "2L12B" panel (that's 2 Levers 12 Buttons) and the CPS2 kick harness that Jassin linked to.I'm just worried about how I'm going to get it hooked up for fighting games. I guess I can just get it, and worry about that later, but it is possible right?
the JAMMA standard only supports up to 3 buttons per player. on CPS2 games like Street Fighter II that means only the top 3 (punch) buttons for each player are normally wired in the cab. So the lower 3 buttons need a separate connector to the game board. This became known as a "kick harness" since in games like Street Fighter II it was used only for the kick buttons.
you could buy that cab and plug in a Street Fighter PCB and play it, but you wouldn't be able to kick. buy a 2L12B panel and 6 more buttons, then the CPS2 kick harness to plug the buttons into the game board and you'll be good to go.
the harness and buyttons will be easy to find but the 2L12B panel might be more tricky.