I have a 14' Lund with 20HP Merc. My most-fished lakes are a couple of smaller no-wake lakes. I have not fished lakes limited to electric-motor only.
My trolling setup is a Minn Kota Powerdrive with ProNav Marine controls for spot lock capability. The TM is a 55# 12V motor. It will pull my boat with two guys at 2-3 mph, and when it's just me, close to 5 mph, which is the limit on those small lakes.
The ProNav setup is good. Like anything, it has pluses and minuses. I provides control from either a fob or my smartphone, has full navigation capability, and keeps the foot pedal fully functional, too. If you want to research the ProNav system, here's the link:
ProNav Marine
I use a separate starting battery; Group 24 lead acid, weighs about 35 pounds. My troller and accessories are powered by a Group 31 100AH LiFePO4 battery that weighs about 26 pounds.