You will need an NTSC camera.
While I'm not anti-Mac, and quite enjoy my Mac, video capture is NOT a task it can do well, or often even at all. Windows was always the OS for video. Not Linux, either. There will be no easy way to get the video from the tape to Mac OS X, at least not with quality.
Tip: Leave the conversions as NTSC. You will lose massive quality forcing the NTSC into PAL, and it is not needed in the modern digital age. (Aside from making documentaries with worldwide sources.)
Perhaps this project is best outsourced to pros? Just be sure to vet the person/company, for hardware being used, software, entire method. Too many "pros" actually knowledge that same (or less!) than you do. So be wary.