You need the tie downs installed in order to carry the camper. If you have some good mechanical skills and can use basic hand tools and a drill you can probably install either of the two major brands of camper tie downs (Happijack and Torklift).
These kits are somewhat truck specific so the likelihood of you buying a camper from someone with the same year model and make of truck and using their old hardware is pretty slim.
You will need both the attachment points that go on the truck as well as the hardware to secure the camper to the attachment points. There are basic turnbuckles or you can upgrade to quicker pivoting/locking mechanisms (Fastguns is one brand).
It may be rather difficult to find a shop to install the proper attachments unless they are a truck camper dealer. I recently sold a TC and told the buyer what to buy. He went to a non-truck camper RV dealer who told him they didn't know anything about truck campers but that he shouldn't need any of the hardware I told him to get. He believed them rather than me and showed up with nothing!
By the way, when you go to get your camper leave your tailgate at home. Also, you will likely need a 7 pin connector in the front right corner of your bed OR you will need an extension cable to get from the rear 7 pin by the hitch up to the front right corner of the bed. Most all campers use the standard 7 pin plug except Lance. Lance has their own special 6 pin plug that comes with a wiring harness.
If you have a plastic drop in style bed liner get rid of it. You will want a rubber bed mat to keep the camper from sliding around. Depending on the model of truck and camper you may need to build a platform to raise the camper up to clear the truck cab. This is mainly a problem with older campers on newer trucks, particularly Fords. Also, tailgate openings have gotten narrower over the years. Again, an older camper on a newer truck can cause fitment problems.
