One of the bigger improvements you can make in a Transport/Dac combo is to break the ground plane between the two components so the transport doesn't pollute the dac
Here's is a cable designed to do just that ... I think this cable will yield more improvement due to isolating the ground noise than spending significantly much more money on a premium exotic type without any isolation
And it comes from the Cable Company who give you a free audition
http://www.thecableco.com/Product/DSIX-Digital-Signal-IsoLation-Exciter-RCA