I seldom visit this board, now I remember why. Please don't take this as me just coming in to stirr up trouble because I am really trying to help.
1. Centring your design around a mame logo is about as lame and played out as you can get. Avoid this at all costs.
2. Halo is a pc game, a pc game you can't play on your cabinet. Even if you think you can, no, you really can't. So it's a really bad choice for a theme as well. I'm not saying you have to base your cabinet's aw on a arcade game, you can do something totally non-game related and It'll probably turn out even better. With that being said, making one based off of halo is almost as bad as that guy who did a zelda cab. The first thing people will ask when they see it is. "Wow let's play halo!" to which you will reply "Well it doesn't play Halo" to which they'll reply "Well that's dumb, why is master chief all over it then?"
Hope that helps.....
The short is look for a better idea, these guys are real helpful and should be able to point you in the right direction.