With that kind of budget and system, my recommendation would be to work with a dealers that carry 2-3 lines of cables and offer risk free trial. Folks at CABLE Co. reminds me of my experience of dealing with a car salesman. You’re far more likely to receive personalized service and expert advice from a specialty dealer than from the ‘Joe Schmoes’ at Cable Company.
And please stay away from cables with voodoo accessories touted as fine tuning devices. It would be helpful for readers to know rest of your cables, like PC and IC’s.
Think synergy when it comes to brands and materials—copper vs. silver, for example. Cables are no different than any other component in your system; they need to work in harmony