Well. I'm using a bi-wire set of Kimber Kable 8TC and have been very satisfied. I know you've got a bigger budget available, but if you've considered the 8TC, there is a 12 foot bi-wire pair for $175 that was just listed today here on A-gon.
Bi-Wire Speaker Cables for Vandersteen 3A sig.
I am looking for suggestions, I have a Classe' CA400 and ARC LS-22. I am looking used at about $600. Any help would be greatly appreciated.