1st note - 25' monitors are just way too big. Unless you have want to have a drive-in movie in your living room. 25" monitors, however, are definitely the way to go. Most cabs with 25" monitors can still be moved through a standard 32" wide doorframe. If the cabinet has a control panel wider than 30", it can probably be detached from the cabinet and moved separately.
2nd note - DON'T look at the monitor and say "I can just have the local TV repair shop fix that" - odds are EXTREMELY good that the local shop will NOT have the equipment to generate test patterns on an arcade monitor, and will not be able to adjust the monitor. Either get one that already looks good, or get a friend who knows how to repair arcade monitors, or be prepared to buy a new monitor to replace the old one.
3rd note - unless you're a handyman, you definitely want to get the cabinet with better exterior condition, over a cabinet with a disgusting exterior condition. Most cabinets are laminated or have been painted over with black latex paint, or BOTH, and neither is a particular joy to fix. Capcom/Dynamo cabinets (IMO) look the best as long as you can find one in decent shape. I know some of you are saying "I don't give a damn I just want one NOW!!" but remember that it is going to be a permanent fixture in your house/apartment. You wouldn't want to have a rusted-out refrigerator in the kitchen, so don't pay any serious $$$ to get a crappy-looking cabinet.