Speaker cables for Kef LS50....

I'm putting together a 2nd smaller computer-based music system in my den, and am looking for some input on a speaker cable for the Kef LS50's I'll be using in the rig. The run will probably be in the 20ft range, and I'd like to keep the used price budget to around $500 but I'm willing to push things a bit for the right cable if need be.

System is:

Kef LS50
VTL IT-85 integrated amp
Meitner MA-1 DAC
Wireworld Platinum interconnects
Acoustic Revive USB

Anyone out there who's stumbled across a cable with some synergy for their Kef's, I'd like to hear about your experiences.

TIA,
Bob