If you find Oracle not to your liking, you can try MySQL (http://dev.mysql.com/downloads/
), PostgreSQL (http://www.postgresql.org/
), or Base - part of the OpenOffice.org suite (http://www.openoffice.org/product/base.html
All are open source and free/no charge. MySQL is big in the enterprise space as well, and they have a paid-version as well. I've been playing with it a bit in making my media PC based on MythTV. It uses MySQL for storing broadcast guides, and for building search indexes based on the metadata stored with music and video files.
I have no experience with PostgreSQL, but it is used in various Air Force systems I'm familiar with at work; nor do I have any experience using Base - although I do use the OpenOffice.org suite. It's somewhat similar to MS Access, but it's really just a front-end to OpenOffice's HSQL database engine, but can query just about any other database engine. My own real database experience ended with Informix on SCO Unix almost 20 years ago. I was modifying an Ericsson telco central office application for use in the US market (T1 vs E1, meters vs feet, MDF differences - not fun...)
I think Oracle or any of these are more than capable of handling your ARES data. Glad to see you're a db wonk and not stuffing it into a spreadsheet...