You need a device that ouputs RGB to be able to directly hook it up to an arcade monitor. (very uncommon for a device to output RGB in the US)
There are NTSC to RGB converters out there that will take composite video(yellow RCA plug) and convert it to RGB. I have one I bought off ebay, but never managed to get it work. :/
Since you're going to hook up your PC to your arcade monitor, it's probably best to get the ArcadeVGA card. Other cards require special drivers/utilities to output the proper sync signals for an arcade monitor, whereas the ArcadeVGA runs at the proper sync rate all the time, much easier to use, espicially if you want to run Windows. People have said that TV tuner cards do in fact work with the ArcadeVGA, so if you're willing to leave your PC on while you're watching TV, satilite, etc. getting a TV tuner card is an option.