Thanks for the info guys. It's a 2016 Y61 GU. Perhaps the +200 will be enough then.

We are heading away for a few weeks coming up, I was thinking of taking some measurements before getting ready (towball, front and rear wheel arches height from ground) then loading up and taking measurements again - just with stock suspension. I know the bike trailer has a towball weight around 100kg and the boat is similar.

I'd just like it to remain level / comfortable for touring and give a bit of extra clearance.

Cheers,
Shane