[Crowbob]

My local carpet places can and will order cut and bound full runners or individual tread runners of any size, quantity and style of carpet. I’d go to a rug/carpet-only store and ask. Price was somewhere around $100/per step depending on choice about a year ago. You can use the same carpet for landings and hall runners, also custom cut and bound as needed.

I’d also go with individual treads. You can remove them every once in a while to clean the steps when necessary. Plus, if your treads are nice-looking wood planks or whatever it’s a shame to totally cover then with carpet, IMO.