The Tybe-B comes to mind. It has a true HHKB layout, an integrated USB pass through hub like the HHKB pro 2 and a classic kustom-like design with a fairly unique mounting style. There are extras available on Cannonkeys, and Sandkeys will have some soon. If you're looking for something more exciting in terms of aesthetics, the Lily by Gok is currently in production and might have extras available. Also, the international sale of the Neo60 Cu is coming, the lower part of which is entirely made of brass, yet it will be the cheapest of the three. The Neo series has amazing value for money.