Seeing the space and floor tile would be helpful.

First, quartz and marble don't mix great together especially if you're going for a marble look quartz. I suggest waiting on the backsplash and probably looking at a something besides marble or a marble look. Second, i don't see much beige in the countertop you mentioned but always go see the slab in person before installing it.

Seems like you're still in the planning stage which is good. i suggest you find some inspiration kitchens you like and start there.

Maybe something like these?