I would say either granite or quartz. I went with quartz in my recent kitchen remodel, and am very happy with it.

The darker the bench colour, the more marks it will show. We have a stone benchtop - a white with small flecks of grey and beige through it - easy to maintain.

White-matte cabinets (flat panel, not shaker) and white bench (or maybe epoxy sealed marine ply??...siriuskey can tell you about that), mirror splash. Love the ceilings. I personally would go for a modern, stream-line, no handles, integrated appliances look. This space has real potential to be very cool, even with the slate. It doesn't need any more more texture or darkness. This is a nice kitchen, you should be able to sell it on ebay.

Thanks bigreader, I will post when finished, I'am hoping for a soft look in an 80's tiled and timber open plan laundry which is full of sun and looks out over the pool and deck. I have some white end panels that match our kitchen to help build it in, our new $50 front loading washer which my son and husband found at a local second hand store, the lock on the door wasn't working so they being the clever guys they are improvised and we now have a very unique handle that I love made from a piece of free form timber. The bench top is only 60cm deep so the machine will protrude a bit, I'am hoping I can get it to work as a wider bench top is a lot more expensive cheers