If you're looking for multiples of 3, they have the S-919 with 9 bays. However, I haven't been able to find any for sale online, and the IStarUSA website lists them as build-to-order.
http://www.istarusa.com/istarusa/products.php?series=Tower%20Case&model=S-919#.Ug7vOHYo5D8