Unless you've got everything else in your system up to your ultimate level I'd say go with a spool of generic 16 awg wire from Radio Shack, Home Depot, etc. that will work just fine. The surrounds are only going to be handling relatively low-level ambient information, so the improvement of spending a few hundred dollars on better cable for this application will be minimal at best, especially compared to sinking that money somewhere else in your system. At less than $10 you should just try a generic spool first as you've got very little to lose. Best of luck.
Tim
Tim