Wood would likely be a more common substance also because it would be a lot easier to mold, hollow, and work with than most metals would, even with the use of magic.
But again, I streess considering how it my by be possible to use other materials within a wood wand, and see what usefulness they would have in folk magic or just literary symbolism.
I also think about how tiger bones have such a create deal of importance in Chinese medicine, and the use of something that was once alive could have a lot of magical potentcy. Bone would certainly be something to consider for a wand material. Maybe even Muggle animals could be used for the exterial as long as the wand had a magical core.