For towing only the maxium tow load capacity and GCWR are important. The GCWR is important as it includes consideration of the engine, drivetrain, brakes, frame, etc. for the total load of the truck, passengers, gear, and trailer.
I would subtract 10% from the maximum trailer rating for a gross trailer weight and subtract another 1,000 lbs. to allow for gear and water and other items in the trailer. What is left will be the weight to look for in a trailer in terms of its dry weight.
Less can be more with a lighter trailer and especially a shorter trailer that is easier to fit into campsites. With the trend toward smaller vehicles there are lots more lightweight trailers being built and many more choices available.