Hey Moonlight, Welcome,
Renting a C 206 is probably a tall order, they are not a common plane in rental fleet - too expensive, and the rental company is not enthusiastic with rental pilots using a 206 as it was designed - to carry six people, or a whole bunch of cargo.
Perhaps you'll get a suggestion, but it you don't, it's probably just because there are few to none available for rent.
What I would suggest would be to find a parachute school who have one, 'cause there are many doing that work. See if they'll put a right seat back in, and give you some dual - but I doubt they'd want you taking it away, it'll be a working plane.