Hello lukeunlimited,
Where are you located?
I don't think you will be able to get top hydroponic researchers to grant you an interview, but the best one I know of is Dr. Lynette Morgan in New Zealand. She is a hydroponics researcher and consultant to large hydroponic farming company's around the world. However she has written many books you can easily buy.
There is also a Mr. Howard Resh who has also written books on the subject. He has a website though I don't know it off the top of my head, and I think he is in the USA. I have a list of books written by both of them here:
List of Books on Hydroponics
Also, if your looking for information and/or people to interview on the subject, I would suggest trying to contact University's that have a Controlled Environment Agriculture program. Both the University of Arizona and Cornell University that I know of that do. Here is a link to the University of Arizona's Controlled Environment Agriculture page:
PLS 217 Introduction to Hydroponics and CEA, If you scroll down a bit you can download the entire classroom handbook they use in pdf. chapter by chapter.