Rear surround sound speaker cables

I have an Audio Refinement preamp (pre2dsp) and amp (multi 5), Vandersteen 2ce signatures and one Vandersteen 2wq subwoofer, Vandersteen vcc1 center channel, and I am thinking about getting the Vandersteen VLR's as rears. The question is how good do the speaker cables have to be that would be going to the rears? I know people spend a lot of money for the fronts, including myself. I prefer audioquest cables.
My HT system is comprised primarily of Vandy speakers -- only the rear surrounds are a different brand (M&K SS-150 THX), which I chose mainly due to space limitations. Given that the Vandy VLR's are not truly full-range (as I recall, the rolloff starts at about 64 Hz), and reproduce mainly ambient information, my personal opinion is that it does make a lot of sense to spend mega-bucks on speaker cables for the rear surrounds.

One of the primary issues in choosing cabling for the rear surrounds is the length of the wiring. My rear surrounds needed about 35 feet of cable, so I originally chose some $1 per foot, 12-gauge Monster Cable that is wrapped in a Romex-style jacket. Then, about 18 months ago, I decided to upgrade the rear surrounds' cabling to Kimber 4TC. To be honest, I can't tell any difference in my system between the Monster and the Kimber cables. As the disclaimers in ads like to say, "your mileage may differ", but my best suggestion is to start out with a decent quality, 12-14 gauge cable (such as the Monster, or maybe Kimber 4PR) and see if they are satisfactory to you.
tlg- i was in your shoes about 1 year ago. ok, we know what cable can do for audio, so based on what i wanted 'more' of in the rear channels, i went to a car audio specialist (they usually carry a variety of by-the- foot cable on some type of spool) and picked up some cable that promised more base definition, and clear highs. from car audio specialist, mind you. again- i only went to them because they offer variety and low pricing. the cable is stiff, black sheathed, copper with silver, 14guage, and i believe i paid less than 1.00 canadian per foot. i was running cheap monster cable to my rear channels originally, still costing well more than the current ones. did i notice a difference? yes, much better than the originals, i could hear extension in the highs, creating more ambience and, during the pod race in "the phantom menace" i swear there is lower frequency info that i now hear. so, my opinion is that unless you are running a serious high end ht set up, i would not spend terrible amounts of money on rear effects cables. but, as any audiophile knows, clear defined highs, fast and detailed, can provide info that will only enhance the ambient spaces so important to good ht presentation. good luck, good ht is highly entertaining and fun. fotis_k