From what I've seen, there are 3 primary brands of HD mud flaps, two companies of which are in WA State, ProFlap and UltimateFlap. The other is Duraflap.
They all are rigid enough that you don't need the weighted version, but I had non weighted version on my 2006 2500HD D/A truck, which I put 60k miles on in 2 years of doing RV transport, and they started to curl backwards some. With that being the case, I won't buy the non weight versions again.
Page one has a photo of my Dually, and the flaps are still in perfect straight condition 7 years and 45k miles later. (nope, I don't drive that truck much)