I wouldn't bother for a 55# thrust. I would recommend at least a 70-80# to take advantage of the 24 volts. You will need to add another battery to ur setup for the stern motor and ff as they can't run on 24v. You might have to upgrade ur wiring on the 24 v circuit depending on the guage of your existing wiring.
https://www.minnkotamotors.com/suppo...on-and-rigging
Other consideration is your batteries. When wiring in series u want the batteries to match to maximize performance. I.e. Same age and size. Don't forget about upgrading the circuit breaker and onboard charger to a 3 bank.
I have an 80# bow mount on my 17' deep v and it is awesome. Drags the boat around all day with 29 series batteries.