Usually cargo capacity of the tow vehicle becomes the limiting factor when towing a trailer. The tongue weight of the trailer should be 10-15% of the total trailer weight, and the tongue weight becomes the cargo of the trailer.
Find out the cargo capacity of the truck, subtract occupants, hitch head, and other cargo,and what you have left is the amount available for the tongue weight of the trailer. Look for a trailer that is no more than 7-10X that remaining cargo weight.
A good rule of thumb is to look at trailers no heavier than 80% of the towing capacity. Then double check the trailer specifics against the cargo capacity available.
