I don't have any recommendation, I have dedicated circuit for preamp and amp, the amp came with important looking cable.
IMO, buy 'returns accepted', just in case you don't hear a difference.
Through Amazon? I would get a couple sets of Nobsound springs https://www.amazon.com/Nobsound-Aluminum-Speakers-Isolation-Amplifiers/dp/B07K9ZYP84/ref=sr_1_1?crid... and then about a half a dozen of these Schumann generators https://www.amazon.com/Generator-Schumann-Ultra-low-Frequency-Resonator/dp/B07WWD17FV/ref=sr_1_26?cr...
Those things definitely work and will make a big improvement. When I look for power cords on Amazon none of the names I tried came up it was all very questionable cheap stuff. So unless someone knows Viborg is good I would go with Nobsound and Schumann. Those circuit boards look like crap and seem impossible but are in fact impressive.
I would consider following WireWorld Power Cord,
Combining the unique benefits of Fluxfield Technology and the best available OCC-7N copper, Electra 7 delivers dramatic improvements in clarity and image focus that can transform a great system into one that is truly exceptional.
I'm not a big believer in tweaks but somebody recommended the ifi iPurifier3 to me and since it was only $129 on Amazon with free returns I bought it. I hear a subtle, but very real, improvement using it on both of my systems. It makes no sense to me and maybe it is simply confirmation bias but I have listened repeatedly with it in and out of the system and it makes a positive, albeit difficult to describe, difference. I also bought an Audioquest Jitterbug for $69 which makes a positive but less dramatic difference. I think the iPurifier3 is worth the extra $60. Try it and return it if you don't like it.
Also, I got the World Wide Cables 12' RCA cable to replace a more generic RCA cable. I didn't A/B test that and I made another change in my system at the same time but I think it made a small positive difference. Emphasis on small. https://www.amazon.com/gp/product/B07FQPB33N
And if you decide to try springs these are the best https://www.amazon.com/gp/product/B08MPVFVRS/