We went with the rotax for the support and the ease of installation. They have been putting the rotax in this plane for a while and they have it done pretty well so we did not want to mess with getting modified engine mounts and a modified cowling. The 912ULS only has 100 HP by my father is a sport pilot who has only flown the J-3 Cub so this thing will feel like he is flying a pilatus porter turbine compared to what he is used to. 1000+FPM compared to 300ish and an increas in cruise by 40 mph....baby steps stinson, baby steps.

as for the floats we are going with the quad amphibious and we expect to probably have a little less than a half day involved in the swap with the right tools. The airplane is already configured for them and we have the compressor installed and all appropriate switches we will just need to drop the gear, bolt on the floats and run the new hydraulic and air lines. Half day to a lazy sunday or so we figure.