Reach out to crutchfield. I wanted to the same thing on a previous MH and they dialed me into a pioneer unit. All you really need is a double din head unit that will accept your camera inputs and either have gps, or will allow your phone to cast GPS to it - in which case you can use Waze or google maps etc on your phone and have it display on the radio. My new F350 does this with the stock radio. The only caveat is you can't view the camera and gps at the same time. You can switch back and forth though. All of this is moot though if your camera inputs are too old to adapt to a newer head unit. But I feel like an adapter can be found for that. You could always go with a new wireless camera to avoid having to run new wires.
Jeff - 2023 FR Sunseeker 2400B MBS