The easiest thing to do for the SG above is to simply make an adapter like the JAMMA one but which goes to the I-Pac4.
I can't take any pics at the moment as my camera batteries are on charge but I'll show you the adapter I have when I can. The fingerboard that connects to the edge connector in the photo above carries the P1 & P2 buttons 4, 5 & 6 on the very right hand side. P1 on the top and P2 on the bottom. On my adapter this goes to the CPS1/CPS2/CPS3 kick harness as Sune describes.
HTH
Cheers,
Ralph.
Coherance of posts inversely proportional to Foster's consumption!!!