I have owned an A. R. E. Z Series on my 2002 ram 1500 and it was a nice cap, for my 2005 Ram 3500 I decided to go with a tonneau cover this time as the last three trucks I have had caps on.
I made a big mistake of buying a Jason tonneau cover, never again will I buy any Jason product and I advise all others to be very careful as that company is a joke when it comes to quality and backing up their product.
I just ordered a Leer Tonneau cover to replace the Jason junk, I like the hardware that Leer has come up with and think they have a nice product.
For caps, I would recommend A. R. E. Z Series as well as Leer products. Florida Line makes a nice heavy duty cap if you have a dealer that handles their brand.
Over all I think if you stick with the following, A. R. E. , Leer or Snug Top you will have a nice cap that will be backed by the manufacture. All the others are smaller company's and cannot be relied on to take care of problems resulting in their warranty being nothing more than a sham.
Again Beware of Jason products, very poor quality.