I'd do the slab on the wall, but do a solid white for the counter tops. With veining that bold, doing the same slab on the counters will be a nightmare to match up the veining. Take a look at both Daltile One Morning Frost or Dekton Zenith for the counters. Get samples so you can match up the whites of the slab vs. the counters.

I am confused as to what you are asking. I think you want to know if you should do the same on walls as counters . I think that will depend on your budget. As for the choice of backspalsh with quartz i never like the look of real marble next to faux marble. Usually in a kitchen a statement slab would go on the island counter and the perimeter would be a simple plain type counter . I do not like open shelving in kitchens and I do like no upper cabinets on window walls if you have enough other storage.

I used the slab marble on my backsplashes and white quartz on the countertops. I had a similar dilemma on my sink wall, which does not have wall cabinets. I ran a shelf along the top of the slab (I am a big fan of Henrybuilt kitchens, and they do this). Here are some photos:

Jackson Heights NYC White Shaker + Paonazzo Marble · More Info

Jackson Heights NYC White Shaker + Paonazzo Marble · More Info

Jackson Heights NYC White Shaker + Paonazzo Marble · More Info

I considered also adding sconces:

But we went with spot pendants instead: