Hey Mark, Well most folks would use a 14x4W on the Saito 82. I would think that the 13x8 would try to pull the plane too fast. Sport props tend to be narrower than the wide blade props like the 14x4w. The thing is you want to get a good amount of air volume over the control surfaces at the lower speed that the Do's work best at.
For break in you could just make a stand out of 2x4's (L shaped) and mount the engine on a engine mount to the 2x4 frame, hold the fuel tank on with rubber bands, and make up something for some kind of throttle control and your done.
I didn't know they made a pitts style muffler for the Saitos. Interesting.....