Remote .ZIP Uploader/Unzipper for Joomla – $7
eXtplorer for Joomla
The best part of these extensions is the fact that they can be used for the purpose of accessing and modifying the various Joomla Directory Extensions and files available on the server through direct file access. Most of the FTP extensions run natively under Joomla but may also be used as independent applications.
MijoFTP – Joomla File Manager
Mighty FileManager for Joomla