(I already have stand-ups of Millipede and Star Wars. If I were to buy another stand-up, it'd probably be Tempest, since vector screens are just intrinsically cooler hardware than raster.)
So, there are four paths one could take:
Build one from scratch, using someone else's plans.
Pro: the controls would be where I wanted them, and it would only cost a couple hundred bucks;
Con: I don't have much woodworking experience, though I could probably borrow the tools.
Buy some crappy game just for the cabinet, and gut it.
Pro: somewhat easier, and about the same cost;
Con: fitting a new controller configuration in might be harder than it would be when starting from scratch. Gutting a game is somewhat sacrilegious.
Buy a pre-built cabinet I can put a Linux box in, e.g,: ArcadePC ($3000 without computer); or MassSystems ($1200); or X-Arcade ($1000, and I think it's a lame `mini'-cabinet.)
Pro: Shit would Just Work;
Con: Jesus, Mother of Fuck! That's a lot of money! Plus shipping!
Decide I'd rather play video games lying down than standing up, and just get a controller and figure out how to get the computer to display on my TV.
Pro: moderately easy.
Con: extremly low coolness factor.
Of course the real problem here would be figuring out how to lay out the control panel so that it works for the widest variety of games. Games are always designed with specific controllers in mind, and the quality of play goes to hell if you're using the wrong controller. (How could you play Tempest without a spinner? Star Wars without a yoke? Marble Madness without that gigantic track ball? Q-Bert without the joystick being at 45°? Even Joust with a space bar and arrow keys is horrid.)
So I'm somewhat worried about ending up with a big mess of controllers that aren't quite right for any game.