RE: What is the best bow string to use?
There are quite a few good ones out there. The shop I work for sells most of the top brand names, but every time I personally work with a customer I order from John (Gibblet/Bucknasty) because his prices are better than any of the top names, and his service is much better. His strings are as good of quality as anything out there, and I believe he is the only person using Halo right now which I consider to be the best end serving material out there right now. I've got thousands of shots on an Apex 7 with his string/cable using halo material with no need for replacement, and these bows usually eat cables quickly.
Send him a PM here under the screen name gibblet. He will take care of you.....