I'm guessing you are asking about electric trolling motors? Bow or stern mount? In any case a 50 lb thrust would likely be more than enough. I had a 50lb thrust Minnkota bow mount on a Lund Tyee 1750 with a 4.3L V-6 I/O, that bow mount did everything I needed it to.
From a Minnkota stand point, 50lb thrust is the biggest you can go in a 12 volt system. Any bigger and you'll have to go 24 volts.
BTW - Welcome to iboats!