Even Mr. V. would recommend trying to shorten you speaker cables. If you are ever able to move to monoblocks, it would make your life much easier.
But, given the case at hand-
I would suggest buying a pair of Audioquest GO-4's, or Rocket 88's, which should be available used at a very decent price. I would recommend the newer William Tell or Robin Hood's but at that length cost will be quite high.
I would also recommend reaching out to John Rutan (audioconnection). He know his stuff regarding cables and won't steer you wrong or try to sell you something.
I also recommend joining the Vandersteen forum (on the Vandy Website), as a Quatro owner, you are welcomed to join. There are many knowledgeable owners that can help you.
Bob