Play to your strength (Street shooting) and don't duplicate what the hired pro is there to do. Therefore, I think the Zorki and/or Canonet would be best.

Not sure how you'd do the formals. The hired pro has a job to do and may not be comfortable if you're organizing you own formals unless he/she is done with those subjects. I might be tempted to use the Super 23 without tripod (certainly doable) to be as mobile as possible. It might mean sticking with a faster film, but a 6x7 HP5 negative is nothing to be ashamed of.