Speaker cable for B&W 703's

I'm thinking about biamping my 703's and was wondering if anybody here might have a recommendation on what speaker cables to use.

Speakers are driven by a pair of Electrocompaniet AW220's and a Musical Fidelity A308CR preamp.

Cables right now are Audioquest (can't tell you the excactly what grade right now).

Would appreciate any input on what cables you would recommend for the upper and mid range and what for the bass. Since I'm not sure what impact biamping the speakers will have I don't want to spend huge amounts of money on this but I'm aware that it won't be for free of course.

Use the same cable(and same length) for both top and bottom. Mixing cables when passively biamping can result in freq. response problems. Kimber's 4TC and 8TC have been around, and very popular, for a long time. It's hard to beat their performance in the price range. Buy them used in the AudioGon classifieds, or on eBay. Or you can just find more of the Audioquest cable you presently own, if you've enjoyed it.
Here's somone selling two pair of 7' 4TC cables: (http://cls.audiogon.com/cgi-bin/cls.pl?cablspkr&1211471382)
Bi-wire...don't biamp.