Do you plan on running newer pc versions of some games, like cetipede?  Or golden tee golf?
You definately want mouse buttons then:)  Like I said, if you want to switch the buttons I have the schematic to use a dpdt relay.
But I will have mouse buttons, they'll just be in the player 
2's button 1 and 2 spot. ( or 2 and 3 spot, I haven't figured
 out which 2 buttons to route to the mouse and which 4
 buttons to the ipac/keywiz..
when you play fighting games like SF, and need to make
 button combo moves, do you usually press button one and
 another button? or are there many different button combos
 (2+4, 5+6, 3+6, etc) to get the desired move (never played
 fighting games 

 )  are they similar button combos
 throughout the fighting genre? or is every game different?
I ask ( because now that I think about it,) there may be
 problems routing a heavily used button (eg: button 1) to
 the mouse along with another heavily used button (eg: the
 2 'most used' buttons for combos in fighting games.. mice
 don't accept simultaneous inputs , do they..) so I may have
 to use a switch and relay with the button outputs after all.. 
oh well, It was just a thought.. trying to keep things simple
 above and below the control panel.. 
