Here is my opinion on the OS for a Mame cab. It is a tool to get to the end result, not some life changing, mind altering, state of being. As such I would go with the area of my expertise. If you are comfortable running the box on Linux and you want to take the minimal extra time to learn Mame on it, great. I think you will find that the functionality and maintenance for a cabinet are there in all the major versions. I am sure there may be a difference between Advancemame on Linux and Windows but I have not found one.
If however, you are more comfortable with Windows and you don't want to experience a slight learning curve to get the cab running then reload windows.
Personally I have found that the installs I have done on Linux work great and I have only had to do some minor work on sound card issues and the like. Currently, however I am using Windows XP because the computer I got (for free

) had it pre-installed. Usually if the box is older I use Linux because I don't have access to Win98 install. If it is newer I am more likely to but XP on it. But like I said for me it is a tool not a religion.