Hello all,
Thanks for all the helpful replies to my original post. Here's an update of the candidates for my neck of the woods (ouch):
1. Merbau/ifelele. The supply seems to be somewhat constrained (not readily available) on the island of Java, but I managed to get a sample (scrap stairway railing). Tony's right, this is very tough stuff, and doesn't seem to be too expensive, IF you can get it. Will attempt to get a bokuto made out of it.
2. Macassar ebony (otherwise known as Coromandel ebony). The information was right under my nose in James Goedkoop's article on wood for training weapons (posted in this very website); serves me right for just skimming the article. Seems to be very tough stuff as well, and not brittle like African ebony. I've heard it's pretty expensive here, but I'll also check this out. Either that, or Adrian can send me his kamagong bokuto...
Regards,
John