Ron,
There's actually a lot of Josh White's material available on CD. A quick check at CDNow lists 19 different CDs. I think that virtually everything he recorded in the 1930s and 1940s is available. What seems to be unavailable are his later recordings on Elektra.
BTW, I've had both Elijah Wald and Josh, Jr. as guests on my show. Both are great guests. I've read Elijah's book and its very good.
Mike Regenstreif