Only thing I can think of would be the Panasonic AG-MX70 - course you're looking at a price tag of about $5,500. Depending on how much each camera is used in the production, the MX4 does have both a composite and Y/C input for each
channel, but switching back and forth between the two requires going into a config menu every time and that would be a real pain and get pretty confusing I would guess :? I've never tried it nor don't even know if it could be done, but could 2 MX4's be daisy chained? Take the output of one into an input
channel of another, and then use that input on the A bus and the other 1 or 2 camera on the B bus? Might get kind of confusing also and vid quality might be suspect - like I said I've never tried it.