I have vsftp set up on a centos vsp. Recently, I started getting a "426 error reading network stream" every time I try to upload a file. I see the error in the vsftpd logs. I tried with several ftp clients and several users. I tried disabling all firewalls on both the client computer and the server.
If vsftpd isn't going to work, you could set up proftpd instead. But if you do that it will need to be configured how I want it. Mostly users chrooted to a certain directory and only certain users can ftp.
You will be given ssh access to do the work.