As an owner of the 9SE's, I have had some time and some experience with a number of cables. below are a few that I liked.
A cable I don't sell, but do like is the My Audio Cables Palladium. Something about palladium that treats the highs very nicely. $599 per pair.
If you want to go over the top, either the Cyberlight P2A with Bolder Cable power supply ($2250 or so for the two), or the Stereovox SEI-600S at $749. The Stereovox's take a long time to break in, but it's worth it. FULL DISCLOSURE: I am a dealer for both Harmonic Tech and Stereovox.
You may also want to consider some aftermarket AC cables, as the 9SE's are very sensitive to power cords and conditioning.
Cheers!