As for trolling motor size, I guess you need to decide how many batteries you want to carry - one , two or three
(extra 120-150 lbs onboard for #27 deep cycle). The trigger seems to be around 50 lb thrust from 12v to 24v.
I have a 50 something (12v)
freshwater version - doesn't spend much time in the water but I do see some corrsion on the end of the shaft after a couple years. The motor pushes the boat nicely except in a stiff breeze. I tilt the big motor up and use it as a leaning post while trolling around - the trolling motor handle extends out about 6 or 8 inches so I'm not stuck right in the corner.
Let's hear from the guys with front trollers - so he gets another opinion.