I am looking at adding a kicker motor to my 1860 Alweld. It came with a Fulton adjustable kicker motor bracket. My question is 15"/20"/25" shaft or w/ adjustable bracket does it matter? What size motor and 2 or 4 stroke. What brand. I will be using for trolling and back up if big motor goes down. I will be using in both fresh and salt water. I was thinking about a 15hp only for putting on a small (14 or 16ft) boat to use in lakes rivers (4 stroke plus would be I could run Kenai?). Any and all help would be great.