The enclosures I use have two firewire ports—Lets say I have three externals—One drive goes directly into my computer via the firewire port. The second cable goes from drive one (second port) to drive two. The third cable goes from drive two to drive three.
I capture directly from my deck or camera to my firewire card—-then to whichever directory I chose in any of the drives. By the way, I use HD Connect by Cineform to capture all my files. As far as enclosures go, I like the ones that Granite Digital makes—-The only problems I have ever had is with controller cards built into the units and I think that Granite’s are fairly reliable. I’m sure other people have other ideas.