Is it possible to order printed black keys and will international layouts be available?
Sorry printed black keys are not made any more by Unicomp, the source of keys for this project. You can buy unprinted black keys though.
Yes international layouts are available. When you are on a product page for a keyboard, just select “ISO” for the flipper arrangement and pick ISO for the key set, and then in the notes section specify which ISO set you would like to order.