Take a look at Optim from Princeton Softech. It has purging for Sales, PO, AP, AR, GL, Inventory and others. You can also write your own custom purge scripts. It safely archives and then deletes your data. We are using it for our North America instance (Windows 2003/SQL 2000) and our South American instance (AS 400/Oracle Database) using a combination of canned, modified and totally custom scripts. Take a search on this site, there was a thread a few months back on this same topic with other suggestions as well.
Gregg Larkin
Praxair North American System Admin
JDE CNC and Security, Websphere, Tidal, Princeton Softech