The first pick up I bought was preowned and came with an ARE fiberglass cap painted to match the truck's paint color. I am now on my third PU and I have had the same type installed on both new ones I purchased. I rarely need to haul anything tall except a lawn mower and then I use a bungy cord to hold the cap from trying to open to the fully open position.
The things I like about the ARE cap is that it has a very robust locking mechanism, you can have lights installed on the underside which is great when you are getting stuff out of the bed at night and it keeps your stuff dry when it is raining (as is often the case when we camp)and you need to have access to the bed.
If I ever had to haul something taller than would fit, I would just rent a utility trailer.
Dick