Fox makes good sense. Keep it light at the stern of the Ariel/Commander. It also makes it easier to R & R the engine. Less chance of doing damage to yourself

MaiKa'i runs a 5 HP Merc two stroke. Plenty of power for most conditions. An 8 HP Nissan / Yamaha 2 cycle, however, is still pretty light (60 lbs?) and will give you the max appropriate horsepower. Someone figured 8 HP was equivilent to a 160% Genoa.

The Nissan / Yamaha / Merc 5 HP four cycle is still small enough to fit in the engine well. Hondas and other four cycle engines over 4 HP will not fit without a lot of modification to the boat. And, they weigh a ton.