When I build a MAME kit to install in a JAMMA cabinet, I mount everything onto a wood board, including JPac and an small audio amplifier (I picked up a bunch of kits a while back at an electronics discount place for about $5 a piece).
You can see the amp in this pic -- it is the really small board:

EDIT: BobA beat me to it ... he's smart and too damned fast on the links!
