Knife and Gun finishing supplies has lignum vitae blocks and scales available. You can find it a bunch of places, just make sure they are dry not green. IMHO it's a boring looking wood. The Argentinian verawood (often sold as Argentinian lignum vitae) is a little more interesting depending on how it's cut.
Copper liner material I just buy the big sheet from a craft store like Michael's or Hobby Lobby.
I know there's a guy that I follow on Instagram that makes glow rods. Probably could find them and liners from one of the knife supply shops online (K&G, USA Knifemaker, Pop's Knife Supply, Jantz, Maker Material Supply, Texas Knifemaker, etc).
When in doubt Google and/or eBay will turn up supplies.
