Best power cable to use for Raysonic 168?

Anyone one out there have any suggestions? I am using a PS Audio Xstream Plus SC. Does it make a difference whether the cable was made for a digital front end or not? Would going to a Statement SC make sense?
I used a VD David 2.0 that was very dynamic but was to forward for my current system. I tried a Purist Aqueous Anniversary and found that to be a good combo with the Ray 168, it created a bigger sound stage, fuller notes,tightened the bass, helped definition and it even changed the CD's (kidding). It brought the Ray close to my CD3 MKll, I thought that was pretty fantastic!! I also tried the Purist Musaeus it had similar attributes to AA but to a lesser degree. What tubes are you using? Are you using RCA or Bal? What are you looking for a power cord to do?
I used a Statement SC and switched to a My Audio Cables Digital.....more open sound, like removing a veil..the PS Audio is good but it smoothes things out at the expense of detail...if you try the MAC order with the Furutech F11 gold connectors....much better grip and a little better sounding that stock Marinco. BTW I hope this is the last cdp I'll ever have to buy and want it to last until the server technology matures.
Thanks for the responses! I am using balanced on my whole system. Tubes are 6h23 Russian Rocket logo from purchased at Upscale Audio.I have no complaints with my set up that can't be solved with upgrading my speakers. I am just trying to get the most out out of my current CDP and system.
Depending on how much you have to spend and what you think you want to improve I would look towards upgrading to Amperex/Mullard/Siemans tubes the Ray responds well to tube rolling and the sonic benefits would be greater than with a P/C. I run Amperex 6922 PQ US white lable( a pair of Phillips SQ miniwatt E88CC 6922) for sale @ $159 on AgoN the same as the Amperex's PQ. Food for thought.
I have not done much tube rolling.I did try some Sylvania 6922 as well as the stock tubes but was not impressed. Quite frankly its quite confusing with all of the tubes available, different labels, and munufacturers and such. Although it would be something I would be interested in. One question I always had with the 168 is do all 4 tubes need to be replaced? I think the inside 2 are for the balanced end. Am I correct?
Oops... I meant JAN/Philips NOT Sylvania
I think that's correct, you can tell by leaving the outside tubes out for a moment, if you have sound your correct (won't harm unit I do it to check when I forget). I read that all four tubes affect the sound, with expensive tubes I run two and two cheaper tubes. My Ray came with EH-6922 and a spare pair of Jan-Phillips, the Jan-Phillips were better sounding to me! Once I heard the fullness of Amperex 6922 tubes i could never go back the sound is that much richer. It is a little daunting at first, here's are some good reference; some descriptions of sounds

also for prices;

general descriptions;

hope these help!
Take out "some descriptions of sound " that is my comment not part of the address!!