I would do a glass splash back [ this can be painted in your color choice to suit the decor ] - taking from the bench top up to the bottom of the range-hood on the wall of the stove. The window is beautiful and I would give anything to have them in my kitchen. I would probably paint OR stain and apply marine grade vanish to the would so that any moisture would not be able to ruin the wood. I would also put herbs or flowers there. Could it be made into a servery for outside maybe ???

Stacked splashbacks always look wonderful!

The all black kitchen looks scary as. Maybe because there's no lightness in there at all.

Will you be keeping the cork tiles on the floor? If so, make the countertop/bench top a similar color. They are both horizontal surfaces. Choose a color you like that has a bit of yellow in the base (ex: tomato red instead of crimson, or lime green rather than mint green).