Ken,
I wanted to chime in here. I agree that CGA is the way to go for MAME if you can afford it with an Arcade VGA; or if you are restoring an original cabinet.
For MAME however, it looks like the D9300 (18v) could be a nice for those who are determined to use a PC monitor (for Vector games maybe). It supports up to 1600x1200 and since it is already decased, it would be easy to install in a 19" cab. I picked one up at that price. I'll send in a review with pics when I get it.
-Todd