If you have an ArcadeVGA, you shouldn't use ADVMAME. DMAME is better. (if you are under DOS).

With an ArcadeVGA you can have real resolution with DMAME. you just have to generate INI file for games using AVRES tool (can be found on ultimarc web site or on AtomicFE web site (link is in the comment of arcade module)).

ADVMAME modify VGA Card register to create custome resolutions , The ArcadeVGA already own most of arcade game orginal resolution without having to modify register.

I strongly suggest if you go for Win 98 (or even better XP) to use a windows version of mame.