I have been collecting wood for 30 years. Every time I travel, I hit the local lumber yards to see what they have. We go to Hawaii about once a year to SCUBA dive and I usually bring back some Koa and Mango so I have a substantial supply while many other wood providers are out. Koa has become increasingly hard to find and quite expansive but it makes a beautiful instrument. Look though the sets below to see if there is something there you can use. I keep the tone woods in board thicknesses (5/4 or 8/4) to avoid warping and so that I can cut exactly what you need. I will send you a picture before you decide and that is the set you will receive.
Pictured here are: Koa, Claro Walnut, Claro Walnut, Sapele (Mahogany-like but much denser), Koa and Indian rosewood.