I have a 17'10" smokercraft with a dual console and walk through windshield. I just installed a 115HP 4-stroke Merc which idles nice and slow but still pushes me at about 3+ MPH. I want to be able to slow that down to 2 or less MPH and need to buy a kicker, a 4-stroke so I don't have to mix gas. A 9.9HP is about 110 lbs and 6HP is about 55 lbs. Which would better serve my purpose as a trolling motor?