I would use both vsftpd and sftp. I've never used PureFTP. I would use vsftpd only for the anonymouns connection, and sftp for the authenticated access. Since the public share is public, I'm sure you don't care that the data is transferred unencrypted, but when you're sending usernames and passwords across the wire, you want to use encryption. sftp relies on ssh, so everythings encrypted. I honestly don't know how to set up either in suse, but I'm sure theres an rpm available for vsftpd, and the configuration file should be /etc/vsftpd.conf. sftp usuaually works out of the box, as long as ssh is running. If you have ssh running on the maching just run "sftp firstname.lastname@example.org" and it should connect. If you will be connecting from windows machines, you will want to use WinSCP
on the windows boxes. If you need more help, hopefully a Suse user will come along and fill the rest out.