Quantity   Component name
6 × IN-12B Nixie Tube Russian Nixie Tube from ebay ($3 each), horizontal display of 0-9 and dot. the 2 and 5 are the same shape, but flipped.
6 × IV-9 Numitron Tube Russian Numitron Tube from ebay ($4 each). similar to 7 segment LED display, except with filament so can be common anode or cathode.
6 × TPIC6B595N High Current Shift Register
6 × K155ID1/74141 Nixie Tube Driver
1 × RTC DS3231 AT24C32 IIC Module From ebay ($5) High accuracy RTC with multiple alarms, temperature sensor, battery backup, and Arduino compatibility.
1 × Nixie Tube Power Supply From ebay ($9). Takes 8-20 V DC in and puts out 60 - 220 V DC (adjustable) and preset to 180V for Nixies.
17 × MPSA42 High Voltage NPN Transistor
6 × MPSA92 High Voltage PNP Transistor
4 × 74HC595 Shift Register