am thinking of buying a new expedition max.

i may be towing a ~6000 lb trailer or boat, but mostly it will be for long distance road tripping. So i want the best ride quality and passenger comfort possible (or else my significant other will not come along for the long rides).
i know i want a towing package, 4x4, the best sound system.
WHAT ELSE would i be foolish to not get as an option.

I have a lot of cross country experience with a lexus RX350, and that size is just big enough for me alone in the car. To bring along a passenger and our dog, something at least the size of an expedition, and probably expedition max will be needed.

as a side question, other than an empty wallet, would i gain anything by considering a lincoln navigator instead?