First off I give credit to the many sources I found right here on Instructables and GitHub to pull this project off. The design of the box and the programming modification to get the Nixie tubes to sequence on start up to help prevent poisoning of the tubes is all mine, but I cobbled a lot of info together to get this thing to work. As we go along, I will point to very good links that helped me greatly as they do a far better job explaining than I could.
Materials Used:
1 - Arduino Uno ($10.00 eBay) - (I tried using a Pro Micro actually tried wiring two different units, and could NOT for the life of me get either to work with the DallasTemperature sensor. In frustration, I switched over to the UNO and had zero issues.
1 - Dallas Temperature sensor DS1820B ($5.00 eBay) - Water proof design, bought 3 to get the price discount.
1 - High Voltage Power transformer board (12vdc to 180 vdc). ($8.00 eBay)
1- Wall Plug Transformer (120 VAC - 12 vdc) ($3.00 at Goodwill thrift store).
1 - 120 VAC Wall outlet plug. ($2.00 Home Depot)
3 - IN-1 Nixie Tubes ($2.00 ea. eBay)
3 - Nixie tube Driver Chips SN74141 ($3.00)
1 - Plexiglass panel (front and for back), Perforated steel sheet metal panels
1 - On / Off toggle switch, cord, wire, solder, hot melt glue, etc.”

Link