These are excellent cables at a very reasonable price…
https://www.lavricables.com/cables/ultimate-silver-hifiman-sundara-upgrade-cable
You obviously also need a good headphone amp so you need to budget for that too. Of course you have to like the sound of the headphones, which is not a given as it’s very personal, or the rest of this is moot. Getting something cheap isn’t necessarily right.
BTW, I spoke with Patrick Cullen about headphone cables and it wasn’t something he was interested in as it’s too specialized and not worth the effort for him. Just fyi.