I would not tow a 25' tt with a Dakota. Also of the Dakota isn't built with tow package installed then you will need to add a heavy duty transmission cooler and get it wired for brake controller and 7 pin plug at a minimum and that is without considering any other issues. Also that 7100 lb tow weight is before you two, any pets, gear and options on the truck.
Your best bet is to find a tt you can live with and get a tv to match. When tv shopping, consider the gvwr of the tt and not he dry weight. I would say 4200 lb dry and 25' puts you in half ton truck, full size SUV or full size fan territory. An armada, suburban, expedition or excursion are good choices for that size. As are F150 (especially ecoboost), Silverado, ram, titan and tundra for truck choices. I would double check the tire loading sticker in the door for "cargo and occupants not to exceed X lbs". Subtract the weight of items, people and pets. The number left has to be able to accommodate loaded (not dry) tongue weight. 4200 lb dry tt will probably be between 5200-5700 lbs loaded based upon what the average people load (could be more, could be less). That means est tongue weight of around 675-850 lbs. Again this could potentially be higher, these are guesses based upon averages. Working that backward and accounting for safety margins I would want something that can easily tie over 7000 lbs adjusted tow capacity and handle at least 1000 lbs payload after accounting for people and gear. That is my personal preferences for safety margins after having been marginal.
