I would agree with Discorules, though I totally disagree with his name.. LOL
All the slick advertising and hype the cable folks spout is just that... slick hype. There is small differences between cable. Note the operative word here, small.
Speaker placement will overshadow any subtle differences in cable.
As for biwiring, try it out. Just make sure to get the length in the biwire cable that you create, as close to exactly equal on both runs as possible.
Have fun and enjoy your RF-3's I owned them now for over 1.5 years and I love them to death. Every night I thank my lucky stars for the sales rep that introduced me to Klipsch.