Are there any dual removable hard drive docks available, preferrably with multiple interfaces (Firewire and eSATA, alternatively just Firewire 800)? The Newertech Voyager fits the bill except it only houses one drive. I need to be able to back up from one external drive to another. There are lots of dual drive docks out there, but none have Firewire. Obviously made for PCs they only have eSATA and/or USB.