If you look on the Ultimarc site, I'm pretty sure that using the Arcade VGA with the D9200 won't really get you anything. Since the D9200 is a VGA monitor, it doesnt support the full range of resolution switching like the 15khz arcade monitors. So in effect, you have a specialized VGA card that will be the same as having a regular ATI card. This also means that you'll have to use hardware stretching with most games, which will result in a less arcade-authentic look. It's really supposed to be used for interfacing normal arcade monitors, and Andy doesn't recommend using it with VGA monitors (if you want to use the full range of resolutions.)
Also, 15khz monitors are generally less expensive than VGA compatible arcade monitors.