This is the OEM Ford Nav Pkg for the 2015 E450, which is also available on the cut-away. Of course, the RV factory would have to order it.
Perhaps you could retrofit one into your coach. However, it probably requires different switches on the steering wheel, and who knows where else, so it might be more bother than worth.
One down side about factory installed nav systems - the lawyers are out of control. I had a factory nav system for my 2009 Nissan Maxima, and almost every function was blanked out until you stopped and then you could use it.
For example, driving along the interstate... you get tired and want to see what hotels are in the area. So the nav system will show you nearby hotels, but only the 5 closest can be accessed. So (depending on where you are), you might only see "Billy Bob's" Motel and 4 of his cousins. If you wanted to stay somewhere safe, say like a nice Hampton Inn, you would have to pull off to the side of the road before the nav system would allow you to view them.
Repeat that for almost every function on the nav system, and you will soon be wishing you had a Garmin portable system.
I got so frustrated with it, when we bought our new car a couple of months ago, we made sure it did not have a factory Nav system in it.