I second Rolmops suggestion of the long shaft motor as long as you can position it in an up out of the water position while going at speed. My 9.9 is a long shaft and is nearly at the same vertical position as the 135 when down and I seldom need to use my EZ Steer bracket I just steer with the big motor and because the props are pretty much aligned it steers as if it was the big motor. The only difference is during extreme wind/wave conditions (and usually just cranking up the speed a bit solves that). If it were me I'd go with at least an 8 horse 4 stroke if possible. Most of the time you just think about trolling issues but in times of crisis (like your big motor dying just as the lightning/storm is starting up) out deep in the lake with nobody else around) you'll be wishing you had a 25 horse kicker I've been there in the past and it's not a warm fuzzy feeling.