Clocks with Nixie tubes always look great and old school. Building one isn’t that hard. Tom has been building one around Atmega328P with Arduino bootloader. His clock uses six IN12 nixie tubes along with 74141 driver chips.
Data to digits are passed through three 74HC595 shift registers. Correct time is kept using DS3232 real time clock chip with battery backup. Clock is covered with acrylic sheet that makes it look good. Three push buttons allow easy setting of time.