First off, the dreamcast is a fantastic system for an arcade machine. Being that it's Sega, a lot of games are more or less direct port from the arcades, and some are inproved. Soul Caliber is still one of the highest ranked games on any system of all time. The dreamcast also has some good lightgun games.
hmm.. so how reliable are those A/B boxes? have you every had any problems with dodgy connection? Turns out PS2 will do VGA and RGB.. looks like I'm going to need an A/B/C box
oh and btw... Will the DC do VGA 31hkz AND RGB (arcade 15khz)? I have have a multi sync but just wanted to ask...
I actually had a DB25 ABC box with PC (mame), DC, and PSX at one point. The problem I had was with the DB25 cables. The wires are very thin and often came loose on me. Recently I scratched the switchbox and went to hardwired controls to an IPAC. I plan to build a pedestal control panel containing a dreamcast and an old projector that will project onto a screen next to my current cabinet.
Edit: Looks like you are referring to ABC for video, in which case I do not know.