First check the tires on your truck. If they have for example a 3200 lb rating at 80 PSI then they will support 6400 lbs. at the rear axle. Get the truck weighed at a local CAT scale where the charge is going to be $10 and then subtract the weight at the drive axle from the total capacity of the two tires.
If the truck weighs 3000 lbs. at the rear and each tire is rated at 3200 lbs. then the payload the truck's rear tires can support is 2 x 3200 - 3000 = 3400 lbs. maximum - this needs to cover the camper and water and gear.
If the tires are OK then the next aspect is the rear leaf springs. For $450 you can add a set of SuperSprings and increase the load capacity of the truck to 4000 lbs. with one leaf or to 5,000 lbs. in total with the double leaf set.
Last is the factory shocks which may need to be replaced but you will not know that until you have the new springs installed and the camper in the bed of the truck.
For wiring try to find a harness that works for the camper and will install as a receptacle in the bed of the truck. The person selling the camper may let you remove the one from his truck. Alternatively there are adapters for hooking a camper into the trailer plug-in for the truck. Important to have the wire for power that runs from the battery of the truck using 8ga wire and to install an isolator between this wire and the battery. This allows the truck alternator to charge the battery in the camper but does not allow the camper to draw from the truck's starter battery.
Depending upon what is already on your truck you may want to add tow mirrors like the GM ones. Another worthwhile option is a backup camera and best place I have found for the equipment and advice is at www.tadibrothers.com.