Well, looking at it again, the first thing I can think of is to make it all light gun games.
There are quite a few in MAME that are fun, and also there are one like HOTD.
I don't even have that great of a computer but it can run HOTD2 I believe.
You could use the new design of the ActLabs Lightgun, 2 of them in fact, and build a new control panel that had pockets to rest the guns down in them. That would rock my face off!!!!
EDIT: This is all for the zombie cabinet.