Why bother with hardware, why not use the cloud? Hardware gets expensive, plus some sever fans can sound extra loud in a home. Maybe someone can give you a heads up on how to do it in Amazon or RackSpace.
I am on OS X, and not one of them can handle the all the extended attributes, resources, and other much you get with Mac OS X Files. Now, most are not claiming to, most will not claim to give you a bootable backup at all. Some do, and they are sorely mistaken.
DropBox is the only one making efforts to, but they are also not even trying to be a backup solution.
Just pointing rsync with a patch on it for the attributes is not enough from what I have tested. Not that I am even shooting for a system level backup. This is more home NAS stuff, and I really don't want to stream a HD video down from a remote store.
Thanks for the comment though.