I agree, ProCite from Personal Bibliographic Software is your best bet. But
here's the hot tip: SEE IF YOU INSTITUTION ALREADY HAS A SITE LICENSE
DISCOUNT. It becomes very cheap that way, but if you buy through one of
those general software catalogues you will have no way to find out if you're
eligable for the cheap deal. Give them a call at 313-996-1580 (I don't have
their fax number handy).
(Views are my own. I have no connection with Personal Bibliographic
Software other than being very satisfied with my dealings with the company.)