An antique kitchen island can add warmth and character to any kitchen. You can buy new reproductions islands, or a genuine antique. Some people would be afraid to "ruin" an antique by doing food prep and daily tasks on it, but you can protect your investment while still having th beauty and character of an older piece.
You can use many types of furniture as an antique kitchen island. An old cabinet structure can be interesting if you have a rustic or country kitchen. A long antique country table adds character and warmth to a french country or tuscan kitchen. An antique commode can make a really cute smaller island. Almost any piece of furniture can be used as long as it fits the desired dimensions and is not too big (or too small) for the room.
When fitting an antique kitchen island to your kitchen, be sure to leave around 42" of aisle space on either side of the island. If you want to protect the surface of your antique, you can have another surface cut to fit right on top. A heavy material like slate or marble might sit nicely and not move around. If you still want to see the top of the piece, try having a piece of glass cut to size.
You can buy furniture to use as an antique kitchen island at antique stores, auctions and even garage sales. If you are very particular, your best bet is to get chummy with an antique dealer and have him scour the countryside for that perfect piece. They'll be happy to do it for you!
Finally, don't forget about lighting for your antique kitchen island. Having the appropriate light is important for task preparation. The preferred method is to use pendant lights that drop down from the ceiling and cast light onto the surface. Depending on the length of the island, you may need more than 1 light. You can even buy some great antique lighting to match the age of your island, or buy reproductions lighting new that will fit right in.