A lot of the time they build a core filled concrete block wall then construct another stone wall against it. The concrete block wall takes the job of retaining while the stone is for looks only. It does depend on what purpose the wall is performing. For example a retaining wall higher than 600mm (usually) needs engineering by a structural engineer which is easier to achieve with core filled concrete block on footings rather than just solid stone. You never mentioned the purpose of the wall which is a vital detail as there can be numerous ways to achieve similar outcomes.

Love love love my QQ Dolce benchtop. Have now decided to go with a tiles splashback and am very happy with the result. BTW, I rejected the original QQ Polar benchtop because it was very white and the sample was a muddier white. QQ was very helpful in rectifying the issue for me.

The Colour palette that I have attached is only a ruff guide line... Are you painting the cupboards in a Dulux colour? What do the cupboards look like, for example the grain? I personally would look at a shade of green colour or blue. My examples might not be perfect as my monitor does not display colours well. What are you thinking for flooring and backsplash?

making a mould and pouring the concrete would be your best bet in getting the look you are after, you can buy the smaller ones but I think the large one you may have to do yourself or have made, lots of info on making them on Pinterest.