That is a nice looking boat. I like the CD brackets that cburger mentioned but I question how well they would work with your long overhang. For one, you would have to climb out of the cockpit
to start the engine
or change the throttle setting. In addition, having an outboard hanging so far back there would have some problems with swamping and possibly boat trim.
Have you looked at the brackets they make for regular double ended canoes that hangs the outboard off one side? You might be able to use one of those for inspiration and build your own out of stainless(or have a local welder do it). The biggest issue that I can see with this is that you might have to remove the outboard and store it in the cockpit
when sailing in a lot of breeze.