I've got the perfect solution for you!!! Several of us have mounted a 9" dash monitor from https://www.rearviewsafety.com
The monitor from here has the exact same connections as on your coach, is easy to install and only requires cutting and splicing a few wires that are easy to get to. I did not connect the trigger wires for the side cameras, just for the rear. Using the monitor we chose you can view all three cameras at the sam time or in numerous different combinations.
Go to Modifications and updates, Jerry's Hurricane mods, the camera mods start somewhere around page 90 something. You'll find pictures, mounting options, and color coding of the wires you need to splice.
Hope this helps and if you need help I'll be happy to walk you through the install, it only took me about 30-40 minutes start to finish.
One of the best mods I have done to date, I now have a nice big clear view of my cameras in an easy to view location!