I doubt any two 19" VGA monitors have mounting points in the same location. If you go with VGA, you'll probably need to get it and open it up and design some sort of gizmo to mount it.
TVs don't work with digital RGB signals, so no, you can't hook it up. If you go with TV, you need to go with S-video. There is some guy on the net who sells a circuit board to convert a TV tube into an arcade monitor for $65 or something.
If you like your arcade monitor, you probably won't be happy with VGA. otoh, a decent VGA monitor will be a lot better for vector games, if you have the hardware to do anti aliasing and high resolutions.
Bob