The G-26 is more than enough to fly this plane. Mine is a heavy pig at 23# but still flys good on the G26. As others said the step and incidence is WAY off if built from the instructions. As far as the float spread, 18" is scale. I pulled measurements from 2 different full scale Beavers on everything before I started mine as far as spread, and mount locations. Then 25% rule is for sport, not scale.

http://media.putfile.com/KMP-Beaver-v2006