I'm picking out accessories for this boat I'm getting ready to order. Since it's my first boat, I have no experience to draw upon, so I will depend on the BOC for it's vast knowledge and advice. The boat will be a Sea Ark 2072 VPLD with a 15 degree hull and a 115. How much thrust in a trolling motor do I need for river fishing? I plan on a 24 volt model and see 54, 70, 80 and 101(36 volts) models. Thanks in advance.