Looks like you've got a 4.0l tow package Ranger. Great vehicle for a smaller camper, but fully loaded you're looking at the trailer weighing more than the tow vehicle! While you can do this, you're bumping near your weight limit. Never good.
If you're looking for reliability and hauling capacity, your idea of a full size truck/SUV is a good one. Full ladder frame, heavy duty components, made for hauling and towing. I wouldn't consider a crossover or front wheel drive minivan (CRV, RAV4, etc.). While their tow ratings have increased in the past 10 years, they really are made for "occasional use" at their tow ratings, and some components like the transaxle and auto transmissions are not built with durability first.
I'd suggest a well-kept F-150/F-250 (or similar) of any time in the past 20 years. Best option would be a V8, although the older Ford 4.9L straight six was an excellent tow engine. Something with a factory tow package would be great because it already has the right gearing (4.10 or so, higher being better), although you could make due with a standard model. Check that all maintenance is up to date, change the fluids, add a good transmission cooler (and a real temperature sensor), and you're probably good for at least a few years of solid towing goodness without any major problems. Also- any repairs are well within the capability of any mechanic, and parts are dirt cheap.
If you don't need the "truck" part, have you considered a full-sized van? Same components, more interior room. I've seen many, many 20-30 year old Econoline vans towing boats/canoes/hauling people well into 300-400k mile territory without major incident.