Most front ends just run off of setup text files, anyways. You can basically install the whole thing on your machine and burn it onto a cd after it's set up. If all his files are in the same locations on his machine, it ought to run just fine by copy/pasting intothe same location.
Simple front ends that would work this way include:
Mamewah (Windows)
Game Launcher (Windows or DOS)
Heck, you could even create a bootable CD that loads straight into a front end like AdvanceMenu or Game Launcher that just points directly at his ROMs. Of course, that's assuming yall share the same stuff in the same places.
Did any of that make sense?