you definitely wont have an issue with 54" on that boat.
I personally have ran a 55lb on my tinner and a 16 foot smokercraft and trust me on this, you basically will always want more power.
I personally hate underpowered trolling motors, they not only drain your batteries quicker, they also dont allow yourself to get out of harry situations when the wind is blowing. i like having full control and power available to get myself out of trouble when i need to.
Go 24v and never second guess yourself again.