You are going to have to do something with the stairs. Unless you know they are there, the same stain makes the stairs blend into the floor. What I have had clients do is use upholstery tacks to line the edges of the stairs. There are great tacks available and the result looks pretty cool.
I like plain old roller shades...come in a variety of colors...simple, almost disappear, and easier to clean than the cellular shades. Don't know why, but spiders love those little tunnels.
Q