I tried reading stuff here regarding this topic, but the only thing I've found out is that you can probably get this if you reach out to the luthiers.
I think Max Rufo has some tone wood stuff, you might want to drop by his shop. I've heard he's using some native tonewoods so he can probably show you where he get those.
Also, you might want to consider ordering online, but it's going to be pricey. (well custom stuff are all pricey).
Anyway, good luck man! Let me know what you find out, i'm actually interested on this stuff too.