Amazon S3 Backup for Resellers

As a reseller I would like to be able to backup all of my accounts to an Amazon S3 bucket. I love this option in WHM. In my reseller account I run a php script to backup the accounts but as soon as someone changes their cpanel password the backup for that account is broken. I get that as a reseller I would not be able to do a full restore myself but if required I could extract the database and website files or pass the complete backup file to the host for them to do the restore for me. This functionality would take a lot of the worries out of hosting many websites in a reseller account. Being able to keep as many backups as I want safely, securely and inexpensively in an Amazon S3 bucket would be fantastic!