There are about a mazzilion solutions to this problem. What do you want the components to look like? What do you want the light to do? What can you spend? Cutting and patching sheetrock is not that bad.

The light you chose is very stylish! For your stairway, here are some potential ideas. I noticed that the Deep Bronze finish on your light is very close to black, so I also considered some black-finished options. (Some of these lights are also available in bronze.) Millennium Lighting 4-Light Pendant Savoy House Berlin Kichler Larkin Sea Gull Labette Golden Lighting Mercer Savoy House Penrose Quoizel Aviary Golden Lighting Payton I don't want to overwhelm you with options--let me know what you think!

Because of the lighted niches, I recommend step lighting.

What led me to this was I was tired of knocking the wall sconce with stuff going up and down to the basement. I used a 3" adjustable gimbal GU10 fixture - it's supported by the drywall (remodel fixture) so no mounting to the back of riser or under the tread. I did need strapping under the stringers to allow for electrical to pass under instead of through (can't remember if I needed the extra 3/4" for can clearance). They are placed 32" apart and give uniform lighting on the steps. So I did wire them first prior to drywall to experiment with spacing and if the 3" spot throw could offer general light (a 4" can wouldn't fit). This was before the recent wafer LED lights, you can get those as well and in 3" or 4", but you need to have adjustable gimbal so you don't stare into the light while walking down the stairs.