It sounds like the Media Composer is not the same computer he plans to use DVD Studio Pro on, correct? I am not even sure it is a Mac, correct? Is it a PC based Media Composer?
If that is the case, I would simply look to export to a compatible MPEG-2 directly from media composer to MPEG-2. Take that output file and send it to the Mac via a FireWire portable drive or a via a Local Network.
In short, the easiest, best way to deal with this in my humble opinion, is to look for a compatible MPEG-2 solution directly from Media Composer. Everything else is going to be a hassle. Just make sure the MPEG-2 output is not a single video / audio output file. It must be an elementary stream file. Video separate from audio. Our common type is a multi-angle compatible file format, m2v and for audio .aif.
You might toss this question around an Avid forum as well. I am simply not clear on what platform your Media Composer is on.
If it is a Macintosh and OS X, you should have the option to Export to QuickTime and just use the Codec that comes with DVDSP2.