What about using a uniform naming scheme. For example, the F.B. Meyer - Bible Readings on the Psalms Commentary could be archived as fbmeyer_psalms_comm_cmtx.zip, with the archive name, File Name: listed above the File Size: on the download page. If the user can't find the download they know the exact name to search for. The archive name also contains the resource extension type.
You could provide the details on the download page:
File Name: fbmeyer_psalms_comm_cmtx.zip
File Size: 489KB
Resource Name: psalmcomm.cmtx
Location: e-Sword Root Directory
The Location: could be a link to a Help page explaining the resource types and where they're located on the various systems, and how to extract the archives to the proper locations. Just one man's opinion