Hi Jen,
I really enjoyed working on this pop for your kitchen! I found a couple of options that I think you may like from your inspirational images. The first is a black leg, gray fabric counter stool (which is the appropriate height) with a decorative nail head accent.
The second option is an adjustable height, metal base stool with a fabric top. You may want to scotch guard the lighter color to protect against stains from the kids. I've also added another site that you can custom order a microfiber fabric if you prefer.
I hope you enjoy your "Pop!"
Happy Decorating!
Jenna