I gave up on MAMEWAH, its too difficult for me to set up, might try emuloader or something else a little easier.
I made my cabinet 25.5 inches wide in the inside, but i shoulda made it a even 25 would have made monitor fit a bit more snug, I ended up buying a WG D9200 27" monitor which is 24.5 inches wide.
Good Luck on your Cab Crazy, make sure you post some pics
Chapel