We have vsftpd service on our server but I didn't find a way to put limits on file size and total space available for anonymous file uploading (doing it via an account will make it harder - as our users are not super-users and even uploading a file via anonymous FTP sometimes is too hard). We need to allow to upload files up to around 20Gb (and the total space should be around 150G).
This answer is almost identical to one asked previously. Simply apply quotas to the "nobody" user. (or whatever your system uses as a "guest" user)