The minimum Sooloos component which would run with an iPad is the Ensemble.
It can run on its own and wouldn't need any other Sooloos component.
Ripping to the ensemble could be achieved with a PC or MAC running Control:PC or Control MAC software.
The Ensemble cannot access the external Raid storage directly to increase its internal storage. However the RAID would be a good idea to back up the Ensemble data as it doesn't have internal Mirrored drives like the TwinStore.
The heart of the Sooloos system is a component which can run a system 'core' these are Control:10, an Ensemble or a Source One, but not a TwinStore or an ID40 card.
So Ensemble works on its own, or a TwinStore and Control:10 works as a system, or a TwinStore and Source One would work also.
Rick