You'll want a counter height stool as dining chairs are not tall enough (dining tables are generally under 30" high) and bar height are too tall. You'll want a stool with an actual seat height of around 24"-26". I have a very similar island and I chose counter height stools. HTH!
http://www.howtodecorate.com/2012/08/how-to-choose-the-right-stools-for-your-kitchen/
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thicker top on island
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