Don't know if you have found something yet, but Home Depot has some Poly Utility Panels (19.95 for a 4x8 sheet) and they are not that heavy and are extremely flexible, which you could cut & and use contact cement to apply. We are using the stuff in our bathroom and also on our mini kitchenette in our Boler and it looks great. It only comes in white but it will be easy to clean since it is poly.

Never mind, I just saw your other photo with the back splash...btw what did you use to for wall covering to go over the reflectix insulation? We just insulated ours with 1/2" foam sheets cut to fit and used contact cement to apply it, now we are going to put up marine grade vinyl on the wall but not sure yet how we will do the seams to get that professional look...

I was thinking about vinyl too but think it would sweat. So still looking for something else.