You might save some time if you went on the internet and searched for bed covers or to a place like realtruck or Amazon and looked at brands available. Then when you see what price range you can aford, Search this forum for that model and see what people had to say. I did that and decided with in a day or 2. I got the Gator folding one for under 300.00. It doesn't roll but folds in 3rds and goes on or off truck with no tools needed.
i myself prefer the soft roll up cover for low price and ease of convenience for loading, however i bought the ford logo branded (made by truxedo company) from ford accessories and not thrilled with the length (approx. 1" too short) bur as other member here in the forum have found a lot of the other brands of roll up covers are same dimensions = too short. it does keep out the weather rain/snow, etc... but allows soapy water in bed whilst going through car washes
I put the Truxedo LoPro on this week and am very happy with it so far. It is just the right length, the rubber lip on the back fits just over the top of the tailgate, easy to install, looks good, and while it flaps a bit at speed I don't notice any extra noise driving down the road. Have yet to see how dry the bed stays but it's snowing right now so I'll know soon!