Based on that second thread, people seem to be saying that games designed for 15Khz work fine on 24(5?)Khz monitors, so your monitor should be great for most games..
(Most games are standard)
As for the ArcadeVGA, I can't tell from the info on the page whether or not they support 25Khz in the BIOS level????
If not, then you are better off just using soft15 or AdvMame...
(and if you don't mind powering your monitor after your OS is up, it's also just as good)