MAD, Neo Babylonian chronology is fixed.
Cultswatter, COJ work, "Gentile Times Reconsidered" is a must read.
I started a search like yours quite a while ago and contacted scholars and got plenty of books. I tried to make it independently so as not to have biased opinions. You quickly understand why the WTBTS basically avoids mentioning secular sources and, in recent publications, does not name the documents in favour of 587 (which they did in the appendix of Let Your Kingdom come). The evidence is so massive that anyone without prejudice cannot but conclude that 607 could not possibly be the year of Jerusalem's destruction.
I strongly advise you to look at http://www.607v587.com/
For a rebuttal of Furuli's work (JW apologist that published a book in favour of WT chronology, and will soon publish a second one) and other info on chronology look at: http://user.tninet.se/~oof408u/fkf/english/epage.htm