ADAT Interfaces

I've been checking out ADAT interfaces to add more channels to an interface. Can someone please explain the difference between the MOTU 896, MOTU 8pre, the Foscurite octopre LE and octopre platinum. Do all these units have the capability to connect to an interface w/ an optical in to add 8ch via ADAT light pipe (or whatever the connection is called). Or is the octopre MkII the only model w/ ADAT connectivity? I'm assuming that the mkII is the newest octopre model.



Thanks,

Adam