@Popeye if you are in the UK, give Naim support a call. They will be able to tell you what they recommend for your system. For me, they suggested a separate consumer unit with 32 Amp type C MCB, 10mm T&E cable, and unstitched sockets. That's what I used - no special 'audiophile' cable, sockets etc.
Had the Spark in today and the 10mm cable is in and all getting connected up next week the same as you Chris as this is what Naim recommended to me also.
Am I likely to hear a sound difference?