The bigger and heavier the trailer the bigger and heavier the truck needs to be in order to pull it. Small single axle trailers can be pulled with lighter weight trucks with smaller engines. Typically the truck manufacturer will print the suggested maximum pulling weight in the owner's manual. This weight should not be exceeded as you could lose control while braking or over load the engine causing it to quit.
Equally important is the trailer hitch you install on the truck. Trailer hitches are not all created or installed the same way and will limit the weight they can pull. Do not exceed the suggested maximum weight or the trailer could break loose causing an accident.
Once you have these parameters, look at your budget in comparison with how many people will usually be using the trailer. If you need room for six people to sleep, you will need a bigger trailer.
Campers today come with almost any feature you could imagine. From air conditioning and television to full kitchens and marble floors. You need to decide which features will work the best for your needs and your budget. If you plan to use the camper mainly to sleep in but plan to do all your cooking and recreation outside at your campsite, you can probably make do with a smaller trailer with good storage space. However if being in the camper is about as close to nature as you want to get, a larger camper with more features will probably work best.
Regardless of the features you are looking for, when purchasing a used trailer take some time to inspect the crucial areas. Ensure the hitch and electric brake system are working properly. Look at the axles to ensure they are in good shape. Also look at the sanitation and water systems and ensure they are in good working order. If any of these items don't work you will want to keep looking.
