How often do you expect to tow the new boat?
If it's beginning and end of the season then your needs are less demanding than regular trips.
We have Volvo XC60 D5 AWD (2.2t towing capacity). Avon Adventure 620/115hp Outboard on twin axle trailer, lighter than your proposed set up.
You barely notice it behind car.
We have also towed it with Peugeot 508 sw 2.o diesel (1.8t towing capacity) and you notice it much more.
Regardless of 1 or 2 axles a heftier towing vehicle would be my choice.
Whether you buy a hard core 4wd or a "soft roader" like us depends on the balance of every day driving versus how often you will be towing.
Let us know how you get on.
I like your choice of new boat btw