I Was going to be converting a Sega Afterburner Upright Cabinet and doing excactly what you are doing,I was going to use THIS
keyboard encoder,and use a CRT Monitor OR a TV as my display device.
I Would Recomend putting Fans HERE:
So have one fan on one side Pushing Air Out,And the other Pulling Air in,So you have some airflow in the case.I Was then going to use THIS
as my Amp for the speakers already in the case.
For some other effects i was going to place a White cathode tube just above the control layout for night time gaming AND The Player 1,Player 2 and the Insert coin button where all going to glow blue.
But,I have no room for my dream yet
And worst of all i cant get that cabinet anymore,the guy i was going to guy it off sold it a week ago