I am working on a revised 2nd edition which I hope to finish by Chanukah - It will contain signficant new material - especially dealing with the issue of rabbinic authority - as well as being better organized. But it will only contain the English translations - not the Hebrew sources. I am planning on publishing the Hebrew sources as a separate volume. The other difference is that it will be softcover.
It will be available through Amazon as well as seforim stores.