Could it be the definitive solution PS2/Jamma

[Darth Nuno]

Look at this :

on this website : http://www.xinga.com/shop/show.php?product=P21150

The description on the website isn't clear... but it seems to be a way to connect Playstation II to a Jamma board  

[Dave_K.]

I believe this is the same board as the MGCD.  It supports PS/PS2, Dreamcast, xbox and I believe Saturn.  Just uses different connectors.  Its been out for a couple years now.

http://www.frolicker.com.tw/mgcd/mgcd.htm

FYI, there is limited support for certain games under certain modes (see the sites game list).  Consensus is its still cheaper to hack it yourself if you are just looking to play a console inside your cab.  If you want to charge your friends time on the cab, then go ahead and try this out.