if you go the lipo route make sure to have a fire extinguisher handy😊. But in all seriousness be carefull with lipo on both charging and discharging.
I use gelcell batteries for my 42" tug for the weight I need as ballast. I still need an additional 18lbs

Thanks Harry. I will investigate your suggestion with the motor combination. If I went that way I will need to double check the ballast of the boat.

One advantage of the heavier batteries is that they do assist in that manner. The same with the Sea Commander that I rebuilt. I use a gel battery in that which has the weight to perfectly balance the boat. Big downside is the limited time duration on the water.

Hi Peter
I think Banggood Surpass Hobby C3542-1250kv or the 1450kv which have 5mm shafts.
Drop the batteries too much weight, a single 3S or 4S Lipo
about 4000mah is about 400 grams.
Brushless car ESC to handle up to 4S Lipo batteries.
Prop size 35 to 40mm.
I have use these setups on a number of my boats and all work well.
Harry
Hobart
Tasmania