Dear James,
I apologize for my very late response to your question. Here in northern New England of the USA we have recently suffered a severe pre-winter snowstorm which has knocked out electricity for hundreds of thousands of us. Many of us have only recently managed to get back online. And then of course there are the end of the semester duties....
My interest in Zoroastrianism is focused primarily on the period before the one that you are interested in. But for the Achaemenid and Macedonian periods, which cover the first half of the period of your interest, there are the second and third volumes of Mary Boyce's "A History of Zoroastrianism" [1982; 1991]. Besides this three volume history, she also published a short history of Zoroastrianism [published by Routledge, I think; my copy of that book is buried in a storage unit miles from where I live].
I would also recommend the work of Oktor Skjaevo, who has recently published a book for non-specialists, "The Spirit of Zoroastrianism," which covers your period of interest. The literature on this period is enormous. Perhaps a visit to the online Encyclopedia Iranica would be a place to start.
Is your interest in *historical contacts* between Zoroastrians and Hindus of this period?