good luck fitting a video card in there. the only ones I have seen done used built in video, I would think any expansions cards (except maybe a low profile) would be much too tall to fit. Those completely integrated via eden boards would be the way to go.
Personally I would love to build a mame machine, using some real arcade controls and a similar monitor.
like one of these
http://www.geocities.com/sbspin/mame/