I would try the Mapleshade Double Helix speaker cables with Plus upgrade. $440/pair with 30-day trial period. I use them with my Mystere tube preamp, CODA Technologies SS amplifier, Rega turntable and Totem Sttaf speakers. I think they sound great after the break-in period is complete.
http://shop.mapleshadestore.com/Double-Helix-Speaker-Cable-with-PLUS-Upgrade/productinfo/DHELIX-PL/
http://shop.mapleshadestore.com/Double-Helix-Speaker-Cable-with-PLUS-Upgrade/productinfo/DHELIX-PL/