Nedd help in selecting speaker cables

I need some help in selecting speaker cables for my system. I have Kef Ref 2 Series 2 Speakers; Bat 31 Pre-amp; Simaudio Equinox CD Player; Cardas RCA and XLR Interconnects - RCAs goes from CD to Pre-Amp; XLRs from Amp to Pre-Amp; I recently sold my MITs Shotgun S2 Speaker Cables. I am thinking about going Cardas Cross Bi-Wire.Any suggestions are very welcome.
Thanks