Best power cable for Whest Audio PS30RDT SE

The gold standard of power cords, the Synergistic Research Master Coupler. The only power cord so freaking good its been made for over 20 years and yet is still competitive with new power cords twice its price. As someone said the last time this came up, "A $1k power cord for $250? What's not to like?"
This is the Reference version
https://www.audiogon.com/listings/lis9e47i-synergistic-research-reference-a-c-master-coupler-ac-cabl...
Might be able to find the original Master Coupler, who knows maybe for less although I have seen them for more. They come up all the time. Me, I would strike while the fire is hot.  

I agree with millercarbon's comment above. I'll also say that a 14 gauge power cord would most likely sound better than a 10 or 12 gauge wire.

Thank you for the suggestion linked ..  millercarbon .. unfortunately I need a schuko plug since I live in E.U 

Hunt around. SR has been selling the Master Coupler all over the world for something like 20 years. One's got to pop up eventually.
If you can't wait for that I would go with whatever SR you can find and afford. Unlike most of the stuff out there that is chock full of faults and so has to be carefully matched the stuff from Synergistic seems to be more across the board in terms of working with different components and systems.

I have found one here in E.U .. millercarbon .. but dunno if it's the same you were referring

Synergistic Research AC Master Coupler -X active shielding power cable schuko and 1,5mt. long