Paigeoliver, I've been thinking about this in the back of my mind for a bit. Here is an idea for the ultimate Mame cab:
Build an open cockpit similar in design to the one you posted, but put in a much larger screen, 27" probably. Now instead of making that back wall 4" thick make it about 18" thick and load the top of with controls for 4 players and a light gun, trackball and spinner. For the sit-down portion I'd put a force feedback flight stick between my legs with a thrustmaster throttle stick on my left and an ACT-Labs GPL shifter on my right. I think I'd go with a 270 wheel, but I suppose you could make some kind of insane horizontally rotating setup as described above to include both 360 & 270 wheels. I guess you might then want want some kind of rotating pedals too so you could get some rudder pedals. May as well get some good racing pedals with a clutch while you're at it like the ACT-Labs ones.
Anyway, just a thought. If you're already going to build the cockpit cab I say, "why not?" If there were any problems with the height of the control panel you could either lower it, or build some kind of platform that players stand on to bring them up to a comfortable playing level. Shouldn't be difficult.
In the end you'd get a crazy nirvanaesque fusion between a full-on flight/racing cockpit cab and a do-all showcase cab. I think it'd look alright too, unlike many other cabs that try to do too much in one cab. It would be large enough, as a showcase cab, to accomodate all the joysticks and spinner and everything without looking cluttered.