I have Bak Flip hard cover bed cover that I made sure had the rack rail side rails with it. Then you order there rack system that lets you have the top rack that hauls my 2 Hobie Kayaks perfectly. Not cheap but gives you the bed storage that is sealed with the roof racks. I have 15 chev 2500 HD CC std bed and 31 FS 831FKBSS TRAILER. Trying upload picture
There are several ways to carry kayaks:
1. The way I do it is to leave truck tail gate up and turn kayaks(2) sideways and secure kayaks in front corner of truck bed and to rear corner of truck bed. Have done this several times with no problem; I use web straps that can be tightened and this will prevent kayaks from coming out or moving around. You can get straps in automotive at Wal-Mart or most building supply stores. I have about 4 feet of clearance between kayaks and camper - the distance will never get closer no matter how tight you turn camper.
2. Truck ladder rack you can purchase at Home Depot or Amazon.
3. If your camper has strong ladder rack you may be able to secure to ladder rack. But most camper ladder racks are not designed to handle bouncing of weight going down road; believe me I tried with bikes. The ladder started coming loose from camper.
2012 Toyota Tundra, double cab with 6 1/2 bed. 10 foot kayaks.