Congrats on the Y62, should be a big grin on your face that's hard to change.
We tow a 3.3T Retreat caravan (just back from 90mile beach on hols) and we use a WDH Hayman Reece setup. The tow bar fitted was requested to be the Hayman Reece to suit the Hayman Reece WDH. Nissans version had all sorts of warnings so just avoided that path. If you do go WDH and Hayman Reece, we ordered the Nissan wiring harness that simplified the install and electricals...apparently plugged into existing connectors without individually tracking down the wires and splicing them. That was just my preference and obviously not for all, I figured the less Nissan do to the car the less stuffed it is when handed over. We fitted the Firestone airbags with the Kevlar sleeves for 60psi air in the back as our towball down weight varies from 260 to 330kg depending if all 3 water tanks in the van are full etc. I tried towing with just the airbags and no WDH, wow nearly wiped the lot off in one go as the front was very light and steering authority had all but vanished. This was while travelling up a hill so some weight would've shifted aft as well making things worse. Since the WDH, no problems, no caravan sway either. Drove back last Sunday with 50klm/hr crosswind gusts while doing 100 kays (was sign posted for 110 but oddly I was chilled for a change) for 4hrs back home. One could feel the van pulling a bit with the gusts of wind but not alarmingly so and no sway induced so just kept going.
Probably a bit long winded but just a quick summary of our setup and how it performs for ourselves.
We recently did a 2" lift from ontrack thru Opp Lock and it seems to be more stable, odd as the CG is raised, but a real crusy drive still. The downside is with the added weight of the Opp Lock bar and Carbon Winch the added nose weight is slightly noticeable if you hoon around some corners compared to stock form.
It's never going to be like my worked HX Monaro but I'm a bit older and enjoy the creature comforts a little more nowdays.
Enjoy the rig.
Cheers BruceR.