Put me in the camp for electric
, as they are much closer to plug
and play... If you have weight capacity and location for their own battery
I installed a hydraulic bow and stern thruster on a boat with Cummins diesels.
I ran into the issue on a boat with out a dedicated PTO. I ended up having a jack shaft welded up that bolted to the crank snout, and couldn't get enough pressure to reach full torque on the thrusters at idle with a pre-existing non-load sensing two stage pump.
I would work backwards from Vetus or one of the other suppliers for the thrusters, to supply the pump and get a matched system so you can utilize it at slow speeds at the dock
. Depending on how tight you are to the dock
, throttling up to use the thruster may complicate things if you are "threading the needle" with current
On that boat we ended up removing the hydraulic system and going with a pair of Gel 8D life lines sitting beside new electric motor
heads for the thrusters.