you might look into access, a word for windows compatible system. the midwest
museums conference has bought it to use for membership and annual meeting
record keeping. i was assured it was incredibly flexible and powerful.  we're
currently using Claris' Filemaker Pro. Work with Access so far has not been
quite so flawless as suggested, but we're moving into it a little at a time.
a new version is out since we got ours, which, i understand has more built in
membership planning info and provision.
i know the western museums association is using an access-based program as
the basis for their membership records, and they have more track record.
feel welcome to call me if i might be of help, or jim hanley at the WMA
office.  i do not have his phone number at hand this moment, but i will find
it to forward.
Esther Hockett, Executive Director, MMC