15 or 20hp 4stroke motor for my jon boat

[bAcKpAiN]

In all honesty, if you need to get on plane ASAP. I would opt for a 20HP 2 stroke. The four stroke is going to add weight in the back that will make the hole shot slower, and have it ride deeper in the water. Honestly a 15 2stroke would probably even be better than the 20 4stroke. But like I said, were it mine...20 2stroke.