Biwiring is a tough call. The difference it makes varies for each system. Most audiophiles, myself included, feel it makes more sense to go with one run of better cable than to buy 2 pairs of lesser cables. There are exceptions, however. In my main system, I use Vandersteen speakers. Biwiring those speakers makes a big difference. More than any other speaker. B&W's are known to benefit from biwiring, but nearly as much. My advice, given your system, would be not to worry about it. If you happen to come across cables you like and they are biwired, get them. Otherwise a single run should be find. If, at some point, you upgrade to more revealing components, it will be more important.
I don't know if anyone has brought up The Cable Company yet. If you don't end up using Audio Connection from my last post, give them a call. They'll send you a bunch of cables to try in your system so you don't get stuck with something you don't like. I use them all the time. Its a great resource.