I have never tried to mix PAL and NTSC on a multicamera shot, nor would I ever try. Does he want an NTSC or PAL master at the end of the process?
The easiest framerates to deal with would be 24pA, on the DVX and 25p on the HVX. Shooting DV on both cameras. when then DVX is captured it will be 23.98P on the timeline.
The PAL will have to resize and get retimed, normally just changing the speed to make the footage play 24fps but that will mess up the sync with the audio from the other camera. I’m almost positive the multicam will not except different framerates.
I would rent another camera at a matching framerate.