Small NW VA looking for Twin Otter possibilities.

Hello,My name is Victor Buck and I'm the cargo dispatcher for Evergreen Sky Aero Service. I am currently researching the aquisition of a Twin Otter to add to our fleet. I am looking for a package which includes both Cargo and Passenger configurations. All possibilities would be considered but the package must include both versions. We cannot accept seperate AC's for Passenger and Cargo types for maintenance reasons...the AC's must be identical, from the same designer, other than cabin configuration. If you have any suggestions please post them here. Your input is greatly appreciated. Vic