Unless you are wanting a new truck, I’d look for something about halfway between those trailers. A 30’ trailer with a Durango is not going to be a pleasant drive. Cross winds and vehicles passing you will not be fun. The trailer wiggling the truck around will exhaust you from being tensed the whole time you are towing.
I totally understand wanting the bigger camper with the kids but I’d highly suggest trying to rent something the size you are looking at before purchasing, unless you are ok with upgrading tow vehicles.