Vandersteen used Audioquest cables for everything they do and they have for many many years. I have the Castlerock biwired, but purchase what you can afford of any Audioquest cable (make sure they are authentic AQ cables if you purchase used as there really are a ton of fake ones on the market) and you will be very happy. Cardas is another brand that works well with them.
Question on cable selection for Vandersteen 1
I have a tube amp coupled to a pair of Vandersteen Model 1 speakers coupled to 15/35 watt tube amplifier. They sound pretty good, but I am using really cheap speaker wire. I am wondering which is the better choice: 14 mm or 16 mm cables with banana plugs? Will the 16 mm cable give me too much base or is the higher diameter the better one in general? I play mostly rock.