Itomaki material question

I’m planning on building a shamisen sometime in the near future, maybe even this summer (doubt it though, since I’m a broke college student). The material for the dou/sao/tenjin will probably be either oak or maple, since these are sturdy woods which I can get in my area for pretty low prices.

So here’s my question: Should I make the itomaki out of a really hard wood, or would that damage the tenjin? I’m hoping to make the itomaki out of either ebony, or a more adventurous-looking hard wood, such as purpleheart or maybe even palm (which might look pretty cool - it’s light brown with a bunch of dark brown streaks). On the Janka scale, purpleheart and black palm rank around 2500 and 2000, respectively. I’ve heard that itomaki should be hard, but I wonder if such a discrepancy between the hardness of the two woods could damage the maruana.

Oh, and one more thing: What type of wood would (hehe, “wood would”) be the best for bachi making?

Hi Tom!
Boxwood, rosewood and ebony are used for itomaki in Japan. Before they used even ivory for it but not so much anymore. There are plastic itomakis, too. For a practise instrument, I think, you can use even maple or other hard wood.

In tenjin holes metal sleeves called zagane are used to protect the tenjin.