Better cables generally bring higher resolution... but that can be a problem. They can conduct some previously unheard distortion or detail which ends up making them sound worse. Or they can tip the tonal balance a little... for better or worse. Different components put together act differently, and sometimes simply don’t sound great. This last one, just not working as you would expect is very rare. I’ve had a number of encounters that have been negative... then with much better components they sounded fantastic.
I recommend Cardas. They are designed to be more forgiving and natural at the lower cost levels and get much more detailed and revealing at the higher cost levels. So I would recommend for your Rotel spend about 10% the cost of the component. Get the corresponding interconnect. I think this is by far the safest bet.
I, unlike lots of folks here tend to stay main stream with wires, known brand that are well established and have known sound characteristics. They know what they are doing and produce consistent sound quality across the spectrum. There are hundreds of interconnect companies out there. Because anyone with a heat gun and a set of wire cutters can make them. There are so many novise high end enthusiasts that are easily impressed by greater detail or bass, but are unfamiliar with the nuances of midrange and other aspects of actual music reproduction, so sounds good to them, but really isn’t achieving what is possible. Then they sell lots by word of mouth, and may not stay in business. It is a lot of work to make cable comparisons... I’ve spent hundreds of ours. Most folks don’t have the time or interest to do it, to be sure they do have optimal ones. Buying Cardas is a great way to get excellent results. When you get real audiophile equipment, then think Transparent, Shunyata, and Nordost. I acknowledge Audio Quest has some good power cords now, but historically I'm not so sure. But where you are at... Cardas. Along the way, if you become familiar with these brands you will be able to shop the verified used market and know what you are getting and not get lost in nearly infinite choices.