I apologize on advance if this group isn't the correct one to post
this question to.

Running Windows 2003 Standard edition (can't do Linux). Looking to
host an FTP server with up to 50 concurrent connections (no
anonymous). Can't use the IIS FTP since the CAL's for 50 concurrent
users will be way too expensive. At this point, we don't need alot of
security...no ssl or ssh but do need individual logon id's (up to
500). I'd like to keep it as cheap as possible but still maintain a
reliable FTP server. Would also like (not absolutely necessary) to be
able to import users from a text file. So out of the
following...which ones are the "best" as far as reliability? Any ones
I missed that are good? Any ones that I should take off the list for
whatever reason?

Bulletproof
Warftp
serv-u (a little too expensive for the corporate version)
Cerberus
Filezilla