As of September 2015, some retailers, such as Wayfair, The Classy Home and AGTStores.com, offer kitchen islands that seat four people. Retailers often sell chair or stools separately.
For example, Wayfair has a Farmhouse Casual Dining Centre Island Pub Table that is 60 inches long and 30 inches wide. It is hardwood with a weathered oak finish. A typical seat height for the island is 23.5 inches. The Classy Home sells a 42-inch long Country Cherry Kitchen Island. It fits four seats when one is on each side.
A Coaster brand kitchen island at AGTStores.com has drop-down leaves that extend the table top from 42 inches to 64 inches long. With the leaves in place, four chairs fit comfortably around the island.