Indeed I do know Koa, as it resides on my aforementioned neck-thru body wings

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It's also certainly available as a solid body bolt on bass. For example Victor Bailey plays a Pensa-Suhr J with a koa body. Check out
http://warmoth.com/frames9.htm for an example. Koa is a beautiful, and good sounding choice for a bass, IMO. Hope that helps...