We use Buffalo Terastation 5400’s for the storage. It has built in backup software that you can set the time, as well as incremental backup (only updates modified/new files). The initial backup is going to take a LONG time, but after that I will just have it run every friday night and it shouldnt take too much. It appears that someone has posted a tutorial on how to link the Buffalo NAS to Glacier, so I think that is going to be the way to do it. Easy choice to spend $60/month on the security of knowing it is off site.
One thing that Im not too sure of is how tolerant Glacier is when uploading a ton of individual files. How would it work as far as overwriting edited files? For example, if I start a project on Firday, it would upload to glacier that night. If I continue working on monday, would it then overwrite the file the next Friday, or would it add to the archive (leaving two files)? That could cause some major issues on our end of things.