You'll likely have to consult an interior designer to source this. I'm in Canada and I have access to a company that offers to the Trade only custom stair runners made to order, with designs to order and colours chosen from a wide range of wools. They are hand-tufted, which is less expensive than hand-knotted, but they'll give you the look you want. These are not available through stores or through the internet.

Thank you. That's very helpful.