Some comments based on varied personal and observed experiences over the years include:
Before you commit to changing your vehicle, take your complete outfit, together with all the equipment that you hope to put in the boat when you are towing it, and find out what the whole lot really weighs! Make allowances for anything not aboard that you expect or hope to to add and leave aboard - especially heavy items like trailer spare wheel?, outboard engine? full tank of outboard fuel? 12v battery? coolbox? toolbox? etc, etc.
Try to keep the total towed weight below 85% of your vehicle's rated towing capacity, and certainly don't exceed it!
When comparing vehicles, try using the PBO [Practical Boat Owner] Towing Index results - PBO came up with this years ago. Its formula was EC(MT/KW] where EC = Engine capacity in CC, MT = Maximum torque, KW = Kerbside weight in Kg. If the result is below 150, forget it!, 150-250 = average, 250-350 = Good, 350-450= Very Good. So torque is the major factor, but these days that can as well be turbo petrol torque as diesel torque.
A front towing ball would be ideal on any vehicle, but especially on a front wheel drive 2x4, since it will keep the weight on the driven wheels when launching/recovering. A cheaper alternative on a 4x4 - less convenient but just as effective in keeping everything clear of salt water - is to have an extension bar, which can be as simple as a scaffolding pole with a hitch on one end and a tow ball on the other, carried on the trailer.
BTW, when you're weighed it, check the rated capacity of your trailer's tyres! It's all too common for trailer manufacturer's/economising owners to fit/replace tyres with less load bearing capacity than the rated capacity of the trailer. I can tell you that it was not funny to be overtaken my own trailer wheel on the motorway... On subsequent used trailer boat purchases, I have often had to immediately replace the tyres either because of under capacity or age hardening cracks in side walls [it's worth learning how to read the date codes on very tyre wall - I treat 10 years as the maximum safe age ...
And a final tip -for safe and snake minimising towing, make sure that you adjust your trailer axle so that you have the maximum nose weight on the towing hitch allowed by the vehicle manufacturer.
Geoff Sheddick
Parker 27/146 "Stroller'