I would call Kevin Hayes at VAC and ask him which tap the 70/70 tends to sound best with - I can never remember, but I think it may be the 8 Ohm tap. I use the 8 Ohm tap because my speakers average between 6 to 10 Ohms. I've used the 4 Ohm taps for other speakers and always had success, but I would ask the question and in any event give 8 Ohms a try - my recollection is that the Sophia is relatively easy to drive (especially for a Wilson), and the output transformers on the amp are very high quality (that amp will drive 2 Ohm loads).
As for the Transparent Reference, they are certainly a fine cable, but I know that Kevin does not like speaker cables with network boxes with his amps. If you have anything else laying around, you may want to give them a shot. I've used Kimber Select all-silver and all-copper, the surprise being that the all-copper, which is comparatively much cheaper, was nearly as good as the all-silver. For the last five years, I've run Jena Symphony, which is the best match I've found.
Regarding Soundsmith, my suggestion is to call Peter Ledermann (he is "Soundsmith") and just talk to him. As noted above, he's one of the lovely guys in audio and he's not a salesman - he'll tell you what he thinks will work best, regardless of cost. He's a great person to talk to anyway, as he is also one of the few extremely knowledgeable people in audio (he's a former research scientist with IBM). Telephone is 914 739 2885 - wait for the options and then dial "9" to talk to Peter. Tell him Drake told you to call.
Good luck.
