My coach came with Corian back splashes, but corian flexes a tiny bit. Maybe less susceptible to cracks. I have tile floors, though.
It is my understanding that the coach manufacturers use a grout that is more flexible than the usual stuff for residential installations. You might want to ask about that at a professional flooring & tile store.
In the galley we added copper tile squares behind the countertop to alter the look a bit. This is actually a faux metal tile, but it looks like the stuff used in ceilings a century ago and comes in several shades of copper. We got one that had a patina to make it look more antique.
There are also floor tiles that are nearly indistinguishable from real slate or stone if you buy the high end stuff, say upwards of $3/sq ft. Those can be used as a back panel too. Might find something that your wife likes, yet cleans easily and not easily breakable. Look around and be creative!
Former owner of 2004 American Tradition and several other RVs
Home is in the Ocala Nat'l Forest near Ocala, FL
Summers in Black Mountain, NC