If you are looking to build a four letter word device, this the way to go. It was deigned by Peter Hand and it was created out of necessity when an infamous scammer refused to deliver the promised B7971 clock design and he had to design his own. The entire device is surface mount components and supports either B7971 of the flat ZM1350 style tubes. The kits is $100 or pre-built (without tubes) for $120.
He also has an IN-17 (vfd) version of this device too. Be sure to stop by his site for more information.