My only experience with chestnut was a 25 gallon chestnut barrel that I had about 20 years ago when I lived in New York. The barrel was from Canada and it imparted a different taste to the wine which I found less desirable than oak. That is not to say that you would be displeased with it but I would urge caution in the amount you make the first time until you are sure you like the taste. It seemed a less subtle taste than oak. I ended up making two planters out of the barrel. I am not sure where you could find chestnut in chips or cubes. I would try More Wine in California or perhaps a Canadian supplier.