I think what you are really asking is for a limited input device. Something that would allow a user to push only 3 buttons (up, down, select) or something close to that. MAME is not what you are looking for but the controller that is used by MAME and other front ends for video cabinets.
Checkout Ultimarc.com and the iPAC controller or u-hid.com. You can use the controller to assign Arcade style buttons to keyboard keys. You can map buttons to scroll up or down and one as the enter key.
Your software front end, should only display a list of videos or sound bites to be played and only need 3 buttons to operate. One for Up, one for Down, and one for select/play.
Hope this helps.
Chris.