Have you considered going the old-fashioned route and using a fairly powerful slide projector? The bottom line could prove to be less expensive over time. The many advantages are obvious. Slides are cheap, easy to replace, modify and update. You need nothing on your display wall but specialized paint, or better yet a 5' x 10', or even better yet 6' x 12', projection screen. For example, see
The biggest advantage of all is, what if you want to display something else? Another big advantage is that you can mount the slide projector just above the elevation of anyone walking or standing in the room. Google maps, and practically all other on-line sources of maps, satellite images, etc., are updated from time to time, depending on the areas which are being mapped and imaged. No matter what mosaic of images you may grab from Google, they will become obsolete before long. So why photograph what you can show updated?
You could bypass any slideshow options and go to direct Internet feeds projected onto the screen/wall. That would be my preference, the live feed. For example, I would love to see Da Vinci's Mona Lisa projected onto my main living room wall via live HD camera + audio feed from the Louvre, live and in high definition. That should be free to the world.