I am using Groovymame and modified Ati drivers that compliment it. they are both available on the groovymame subforum. I'm running them on an HD4250 on XP64. So far all games fill perfectly after adjusting monitor settings. The monitor I linked to stores multimode settings.
Thx for the info. I had not checked out Groovymame yet, looks like it may do a lot for you.
I'm considering ordering that same monitor. I'm in a similar boat to the original poster, accept I've just put off building my cab for years an now all the options for decent realism are drying up 
Did you have to adjust the screen for each of the games you wanted or just specific resolution sets that most games play at?
When you say it will store multimode settings, can you give an example? Do you mean something like you load up game X and get it looking just right on the monitor and based off of the given resolution/frequency it will remember those tweaks next time it loads up? Or something else completely? Does it ever forget them?
Thanks again for the info, trying to make sure I understand what i'm getting myself into if I spend the money on the monitor
There will be some sort of limit on the number of modes the monitor will remember the settings for, but I don't seem to have found it yet. I have a little over 100 games in my 'favorites' list (horizontal and vertical, ranging from low-res games like Missile Command up to Dreamcast games running at 800x600), and after adjusting display settings once, it has remembered them.
It seems to remember settings based on the number of lines displayed. There's less variation in that number than in the number of pixels across. For example the h-stretch and v-stretch settings for 640x480 and 600x480 would be the same.
Prior to this monitor I used a 25" Wells-Gardner Std. Res monitor, using Soft15kHz. This new configuration using doubled resolutions is much more serviceable. When doing maintanence on the computer, almost all the modes are big enough to actually use the pc without buttons being forced off screen, and if I take the PC out of the cab, it even worked properly on an LCD monitor (though the monitor did display an "unsupported resolution" message on a few of the oddball modes, even as it continued to display it).