What would you get today (for use in the US) if your parameters were max weight 60# and max HP 10?

I like the concept of the Lehr propane units but question their quality and service/parts availability. (It solves the crappy gasohol problem, and propane is widely available.) The Torqeedo also is attractive but how do you lock those things at a dingy dock? (would seem to be an attractive target for thieves). The conventional gasoline 4-strokes in that HP range are noisy, vibrate intensely due to their one-cylinder designs, and have low power/weight ratios compared with older 2-strokes.