Hello Pete
As a long time Alembic owner In have several pieces of advice
1) Good things come to those who wait. Don’t jump into anything and be patient. Some thing that meets your needs will come up.
2) Focus more on functionality than looks. While koa is pretty, Alembics of all woods are gorgeous. My first was walnut, I then had a custom made in walnut and now I’m partial to Alembics made of that wood.
3) Don’t just look here and on Reverb but try Craigslist (be careful) and a variety of other options, and
4) Be willing to purchase an instrument that needs some tender loving care. If you are willing to do it yourself use the experts here as a resources. If not find a luthier who is interested in learning about not doing things the easiest way but the best way.
Good luck with your search.