[Bigshot]

Depending on the use, twin 60 Merc 4 strokes are the lightest but 120hp may not be sufficient. Twin 90 Yamaha 2 strokes at 260lbs each would be a great choice like said above. With a flotation bracket like Briguy has the extra weight should not be an issue but a single 150 Ficht would be faster probably than the twin 90's.