The height of your "Island's" eating area dictates the type of seating you'll have.
A 28 to 30 inch height counter works best with a chair.
A standard-height 36 inch counter is served best by a low stool
A 42 to 48-inch counter requires a bar stool.
The only difference, of course, is the style of the chair or stools.
We have many sources with high quality in surpurb designs of both.
Give me a call, I will arrange to show you what we have.