Make sure it has the 5.3 motor and 3.73 rear end. A really good all around suv. The 3.73 gear is a good puller and gets decent gas mileage even when not pulling a boat or trailer.
Aluminum or Fiberglass boat? I used ot have a 20′ centeconsole offshore fiberglass boat when I was stationed in Florida. I pulled it with the wifes current vehicle(2000 ford explorer xls 4.0 litre v-6 2wd) without any problems whatsover. The boat weighed 3500 lbs empty. I figured about 4k with all the gear and gas.