Yeah, I understood that, I was merely pointing out that while you could skip the storage drive entirely it would restrict the amount of recording you could do quite heavily.
SATA standards are fully backwards compatible, you won't get the bandwith of SATA III but it won't cause any problems with your drive at all. Cables are completely indifferent to SATA standards, there's no such thing as a SATA II/III cable.
Enjoy your new drives!