@lloydc - I've tried Viborg products and found them to be pretty good - I've tried their Power Plugs/IEC's and they were well made from silver plated copper. But I do prefer the Sonarquest (also form china) Power Plugs/IEC's, Their IEC's grip like a vice. Also tried Vanguard products, but still prefer the Sonarquest
For Interconnects and speaker cables I use KLE Innovations RCA and Bananas - both silver plated copper. I've found they convey more details and a clearer, more spacious image.
Not sure if you have seen this thread - it has lots of info regarding different wire combinations/connectors tried on the HELIX DIY cables if interested - It's a very long read though
https://forum.audiogon.com/discussions/duelund-conversion-to-diy-helix-geometry-cabling.
Regards - Steve