There is no correct answer . If you ask 100 people you'll get 100 different answers. In my opinion , ETECs are the most advanced . They are also the newest 2 strokes you can purchase . They also run the cleanest .
3 carbs are a good choice as well. They are the generation prior to ETECS, but they produce wonderful power and are quiet , smooth and efficient . From a reliability standpoint it would be a good idea to get the newest 2 stroke you can afford. The newer the motor the more expensive it is. The older the motor , the more affordable.
Personally I think it's a terrible idea , no offense. Lifting anything over 120 pounds off the back of an inflatable boat at the end of a long day of boating is never fun . Doing it on a consistent basis, you'll soon find out that you'll wish you had picked a lighter outboard . Go to the gym, stack two 45's on a barbell , pick it up , then walk around. You'll see how cumbersome it is. I go to the gym every single day and can lift hundreds of pounds, but that doesn't necessarily mean I would want to do that on my days off when I'm trying to enjoy time on the water .
I think you should get a 15 HP . They're just under 80 lbs dry . You can lift it with one hand by yourself .