Howdy Carol. I just bought one of those Time Life DIY books on masonry. They claim that Masonry steps made of a cinderblock shell and filled with sand, then bricked over is less costly and easier to build. Instead of the stone you mentioned, you might be able to get away cheaper with some kind of decorative brick. Or if you prefered stone, then they would adhere as well. I'm no expert on masonry, that's why I purchased the book.( I plan to take on the job of pointing my 3 story home.) They require you to have a 4" poured concrete pad, before the blocks are laid.