Hi Pine,
you may want to evaluate CiviCRM. It is not perfect but supports accounting (rather than just recording donations as before) about a year. The advantage of CiviCRM is the fact that it integrates membership management, mailings, donors management and that it can be used centrally by all the committee members.
The setup and customization is not so easy with CiviCRM but there are plenty of people in the movement who gathered some experience with that.
/Manuel