I can suggest
vsftpd (Very Secure FTP Deamon)
Features
Despite being small for purposes of speed and security, many more complicated FTP setups are achievable with vsftpd! By no means an exclusive list, vsftpd will handle:
* Virtual IP configurations.
* Virtual users.
* Standalone or inetd operation.
* Powerful per-user configurability.
* Bandwidth throttling.
* Per-source-IP configurability.
* Per-source-IP limits.
* IPv6
* etc...
more info @: vsftpd.beasts.org/
anoter hint is PROftpd @
www.proftpd.org/