For my 2-way front-channel LRs, I use AudioQuest Double-BiWired KE-4 on the treble and KE-6/8* on the bass/MR. For my 3-way center, an Aerial CC-3B, I use AQ DBW KE-6/8 on the MR/treble and very-inexpensive Type 6 on the bass.
I too love the sound of silver-conductor speakercable when executed correctly, and AQ seems to do it VERY correctly. I had bought a pair of used AQ Argent+ cable that is comprised of 2-different-sized silver conductors--19- and 21-gage--and 2 pairs of 17g. Functionally Perfect Copper-6. The silver conductors sounded much better than otherwise-good-sounding copper-conductor cable, that I actually considered remaufacturing my own multiple-silver-conductor cable. However, I came to my senses (I think) and bought new. EVERY change to my system this year has improved its sound, and this new AQ cable was a BIG improvement, even over the older silver stuff I was using.
Gorgeously smooth, clean, detailed treble and midrange, and tight, tuneful, authoritative bass--what more could I ask for?
* AQ introduced it as KE-6, having 3-different-sized (17-, 19-, and 21-gage, I believe) pairs of super-hi-quality silver conductors. It now has 4 pairs of conductors--16-, 18-, 19-, and 21-gage, which makes it lots easier to single-biwire with. Same with the all-copper CV-6.