One idea for a memorial to Ray Franz:
Donate his two books to the local library.
They can also be obtained from Freeminds.
I found when I have donated these to libraries in the past that it helped to include a brief note with them. I said something like that they are modern examples of banned books and I gave a very brief explanation of how Jehovah's Witnesses have been told not to read these books that were written by one of their former leaders. (Librarians love to circulate banned books!) Keep your note brief and to the point, however.
I know that Witnesses who are searching use public libraries to get information. A few years back I donated Crisis of Conscience to a library in my home town. When I went there for a visit I met an ex-JW who told me that he had read the book I had donated to the library and he had found out that the book had been checked out over 50 times! There are some Witnesses who might be leary of being caught by parents or spouses at apostate sites on the Internet, but reading a book off a shelf of a library is less threatening. And Ray's books are perfect reads for searching JWs.
Besides the money spent on getting these books into the library will go to a good cause!