Id go with 2-stroke. The RPMs are higher, and that makes for the engine not bogging down as much as a 4-stroke would. When you run a 4-stroke, you are going to have to run a very large low pitch prop, that is also swinging very slow. When you run a 2-stroke, you run a low pich but not quite as large of a diameter, yet you always have the power to pulll out without it bogging.