Add-on to view live and archived data

Because of the high volume of data in our  invoice history detail table, many reports that use this table take forever to run.  We know we can use the purge utility to purge older invoices (after making a good backup company), but we often need to look at or report on complete customer history.

Does anyone know of a way in Sage or possibly a third-party tool, that allows you to look at data in Sage from multiple companies, but at one time.  For example, look at all invoices in our main company AND in our 'archived' company at one time?

Thanks.