It looks to me like a very narrow stairwell and adding stuff to the walls only will make the stairwell feel and look narrower Also adding another different wood element to 2 already is not a good idea IMO. Maybe wallpaper but again depending on that choice .

The flooring upstairs will be changed to either tile or the same lvp as the basement. We’re going in stages (slowly)

The doggie is a cutie for sure lol.

With such a big build-up I wonder what it all leads to at the bottom of the stairs.

There is no program that can do what youi want, only fancy software-- but-- you can use any draw software to cut and paste your colors and shots of your wallpaper and other samples onto your photo to at least visualize.

Also the stairs are just shy of 4 feet wide- is that considered narrow?
I also forgot to mention that I would like the vertical slats/shiplap painted black. Definitely should have re-read before posting. 🤦‍♀️
We just refinished our basement but the stairway does not remotely fit the vibe yet. Excuse the mess, we live here.

4' is not naroow but shiplap is avery dated look and I acconet see any reason for a black wall but if you forego the ship lap and do a wallpwpe then maybe one with some black in ti but IMO no black wall in a enclosed staircase

https://us.naturewall.com/products/slatwall-acoustic-charcoal-black

That is slat wall avery different thing.

Thank you! Super helpful!!

Your dog is adorable. Your basement looks like a large fun space. Glad you are scheming a nice stairwell for it.

Wallpaper and slats are too much in the same stairwell. One or the other. Slats and hanging lights are too much. If you are doing slats, do recessed lighting.

I'd only do slats if they were a lighter wood stain where you could enjoy the character of the wood. The pictures of black slats are so flat and lack so much character. I think Beverly's painted walls would make much more sense if black is what you are going for.

I'd love to see Beverly's black wall with crisp white opposing wall and ceiling, and a quality modern wood handrail that matches your stairs. I kind of also want a pop of cognac in here somewhere to echo the leather in the basement.

Cleaning between slats seems like a major PITA!

Having one wall with slats will look odd, IMO. I would not put a shelf on the ledge, because there are times when you want to the width of the stairs. Equally, a hanging lamp might hit someone's head or whatever big thing you might carry up the stairs.

I'd stick to pictures on the wall. You can take them off when you want to carry a tall bookshelf or big mattress up or down the stairs.

I'd go with light slats and retain the recessed light.