A unique website dedicated to fishing information from Florida's Northern Big Bend. This includes the area from the Econfina River west to the Apalachicola River
Get all that "Skinnywater". I hope your decision is easier now. I'll say this: The one thing you can't get but one way is "experience". If it was my money I'd listen to the guys who have already experienced this and spend your money accordingly. They've been there / done that!
Most of tese guys have already told you what you need to know. If you're putting it on a 21' boat, and expect to mineuver around bars and rocks, I'd get a 101#, 36 volt motor. The first time you get blown up on, or the current takes you up on an oyster bar or rock pile, you'll be looking for all the power you can get.