Fred Little wrote:
It is difficult to find someone qualified to teach this material either in or out of Japan, and finding quality instruction in Sanskrit, or Shingon & Tendai is more likely (though not necessarily easy), and more likely to be sound in and of itself.
At least, that's my story and I'm sticking to it.
Hope this helps,
I have just finished reading Inochi and found it extremely interesting and thought provoking. As you mentioned, additional resources for the study of this material is extremely difficult to find, but I keep searching.