I built one of these. I bought a arcade1up SF2 cab and converted it. Changed the joysticks, the buttons, added an amp, and of course a Pi. Had a 500Gb image on the card, and had over 13000 games from all systems. Was a great machine, but we just didn't play it, so I sold it. You can make a decent cab out of those arcade1up ones, with the above setup for about £500-£600