Thanks for the reply. I am driving several hundred miles to pick it up. The seller has pulled with a Jeep Wrangler Unlimited without a WDH. In theory, the Xterra has more capacity. I plan to come home dry, so if the specs are right, I should be fine on tongue weight.
I plan to get a WDH, but do to the double stack frame members, I am hesitant to buy one without seeing the trailer up close. I think the Reese Strait Line WDH should be a good fit, integrated sway control at a 600# max tongue weight. I don't plan on towing with a quad, just bikes, cooler, firewood etc., but assume the trunnion bars can be swapped out for heavier load.
At any rate, I will bring several ball sizes, a sway bar adaptor plate and a friction sway bar. Hopefully no surprises on the way home.