Thanks for the reply bud.
Hmmm, I don't think that it will advantage 3 & 4 by using USB controls, players 1 & 2 get to stand right in front of the screen on real arcade controls,
3 & 4 will be jostling for a view between us.

Suckers, at least it will teach people to get here early on game days!
The controls I've linked too are just an old PS1 design from the looks of them, I'm guessing most people will be able to get a feel for them pretty quickly.
I'll probably disable the turbo buttons on the controls just to be sure no-one takes the easy route out.
And while it's sort of on topic, are there any 4 player 'Raiden' or '1944' type games?