This is a super old thread, but I might as well provide an answer!
Archive.org is the best place to get these installers:
- Episode IV original installer
- TethVer12513 client (Note: This is generally the most popular choice for local private servers)
- US PSO BB installer
- JP PSO BB installer (This is the final installer shortly before end of service)
Please note that the actual vanilla install of the game is useless unless you know how to uncompress the client and patch out GameGuard. This is why Tethealla is so popular - it's an unmodified version of the final JP client that comes with English localisation files and GameGuard patched out, along with being uncompressed for easy hex editing.