DUDE!!! Use those component inputs!!!

You don't need an Arcade VGA card if you are using a TV or PC monitor. Only time you need an ArcadeVGA is if you are using an arcade monitor.
Keep your current card and get a DVI-to-component adapter and some component cables. The games will look awesome!!! Especially the old-school games like Centipede, Defender, MsPacman, etc...
If you are not all that into the old-school games it probably won't be a big deal using S-video.
Newer style fighters and shooters will look fine with S-video, but the older games will look yucky with S-video compared to component inputs.
I am using a 27" JVC with component inputs and my old-school games look absolutely amazing!!!
You must set the dip switches on the adapter for 480i and run the MAME games at 640x480 resolution. You may get some overscan, but you can just go into the service menu and decrease the vertical size a tiny bit.
This may affect the look of your console games so you may have to experiment.
Otherwise use S-video for your MAME fighters and shooters if you are not that much into old-school games.