- is the Arcade VGA card + breakout cable pretty easy to hook up? Is there any chance of this setup not ultimately working out (if I'm going the easy Arcade VGA route I want it to be foolproof)?
Very easy to hook up, just follow the labels on the wires of the breakout cable. One possible snag is that most monitors in Nintendo cabs use an inverted color scheme, and you might need to build an inversion circuit (there was a thread on this not long ago). But, it might be fixable in the ArcadeVGA's software (I haven't tried with mine, since it's not hooked up currently).
- Are people pleased with the results from an Arcade VGA card?
Eveyone I've heard from that has one has been happy with it, and I really like mine.
- About not going the Arcade VGA route: Right now there's an S3 card in there, which I know will not work. I have access to a Matrox Millenium. Would it be viable to reprogram the registers on this card?
Arcadeos lets you use most cards when you set the incabinet=1 in arcadeos.cfg, however you can't turn on the monitor before arcadeos loads, or you could damage the monitor (as the card will output 31kHz until arcadeos loads). I've never heard of someone re-writting the rom of a card to change the output before, so that's a dead end if you mean that (with the exception of Andy and the ArcadeVGA, but that has further modifications other than just the rom).
I think I'd be comfortable with splitting a VGA extension cord and hooking it up properly
Though not as easy as a pre labeled breakout cable, it's still quite doable (I've done it before, just requires some time, a VOM and a steady hand, as those pins are small)