Why plastic for backsplash when you have real stone for the counter. and a backsplash already. Is this planned for behind the range ? If so no way.

I think what you already have is lovely.

I don't think I would mix two different slab materials. I'd either keep what you have or remove the short backsplash and choose a tile. That sort of pattern also looks like it's made for large expanses, not short runs of backsplash.