Furrion and Swifthitch are probably two of the brands that can handle a wireless signal without drop outs and have some durability.
I've decided a direct-wire model is in my future. I won't have any problem pulling wire from the back of the trailer to the front and from the back of the truck to the dash. I also have no problem with connecting that extra wire connection to enable the rearmost camera.
Currently, I am thinking I may be able to make the trailer connection at the truck's umbilical bracket. If I get really lucky, I'll use XLR connectors. They are a very durable connection, used in stage work, studio, and for balanced sound applications. XLR connectors lock when inserted into the proper receptacle, have all the electrical contact surface inside the housing, and mate with all sorts of durable wire. It's also easy to source RCA with XLR wire sets, RCA adaptors to XLR, or a variety of DIY connections.