I've used a company called "Checker" for their "Checkmate" soft bed cover. Sent them the dimensions and they fabricated the frame to fit my specific bed. You assemble it. All the components are included, their service was great and the cost was under $200. Obviously you aren't going to get Gaylord quality for that low price, but it's a good alternative to the higher priced units and it's custom-made to fit your specific application. Hope this helps.
Dave