For not a lot of money is the IXOS 6003 which sells for $1.49 per foot with free shipping at www.AC4L.com (Accessories for less). Just buy double the length you need, and use double runs to biwire. Just combine the wire at the amplifier end, and the 4 separate ends to the terminals on the 601s. So if you need 8 feet to the speakers, then purchase 32 feet for about $50. You could add crimp on spades or pins if you like.
You will also finds some nice deals on used bi-wire cables at The Cable Company (www.usedcable.com). There are usually muliple pairs of Audioquest and Wireworld bi-wire cables at reasonable prices. I believe they have a demo/return policy as well, so you could try a few.
If you can afford new, then a Bi-Oval pair of Analysis Plus "Clear" would match well for about $190.00 list for 8 feet ($161 for 6ft), or get the A Plus "Clear" jumpers $59 and some single wire. The least expensive biwire Analysis Plus the Bi-Theater 4 which is only $115 for 8 feet ($97 for 6 feet).