I dunno what vendors have them, but I've got a hackberry stave left that has been dry for almost three years if you want it. It's not flawlessly straight and clean, but it isn't bad. PM me if you are interested. It's been lying around and somebody ought to make a bow out of it. I've made two and am working on a third from the other staves I split out of the tree.
Come to think of it, I mis-spoke. Hadn't made it through my coffee yet. Pine Hollow Longbows (Mike Yancy) lists hackberry and hickory staves. He's a fine fellow to deal with, too.
