If you have a 5th wheel, you'll need a tonneau cover that not only locks, but is not too difficult to remove. Not sure how much the 5er hitch protrudes above the truck bed, but if it doesn't, you might consider an Undercover. We've had one of those since we've had our truck (which is now 7 years old) and have been pretty pleased with it. Be careful with the fit when it's installed, though - ours has rubbed a bare spot on one side of the truck bed. Locks seem to work well. It's relatively lightweight, I think about 30-40 lbs for the cover; the two of us were able to take it off without a lot of hassle.