At a minimum, you need disc brakes and a booster. You could tow a small popup all day. Ours was 1200 lbs and 12 ft total length. I barely noticed it, didnt even dent the mileage of either truck. (Usually it was better with the trailer because it was largely highway)
16ft of hard sided camper is at my upper limit now with a Bronco equipped with 1/2 ton brakes, hydroboost, brake controller and a sway bar. I would recommend f/r sway bars. This camper is fairly light at 2600 lbs, but has serious wind drag and is tall. (Off road package)
I would not exceed 3000-3500lbs for a camper. My flatbed is bigger/heavier, but more stable towing due to lack of wind influence and being longer.
I also have a full cage just incase.