Ordinary contractor wire is fine. Easily the best and most cost-effective thing you can do is run one 20A wire direct from the panel to your system outlet. What people call a dedicated line. Really just a direct line from the panel to the system. Then run another circuit for everything else in the room. All the lights and other outlets can go on another breaker.
Because otherwise, the way homes are wired they go from outlet to outlet, each one adding connections, each connection generating micro-arcing adding noise to the line. My room started out this way. Then I changed it to a dedicated line. Big improvement. Then over the years I went to larger gauge, had the wire cryo'd, changed to 240 with a 120 step down, and some other stuff since then. Each step was an improvement. But the biggest by far was just eliminating the connections with the dedicated line. This was also by far the least expensive.
Audiophile AC outlets are also worthwhile. Not as big a benefit as the dedicated line. But well worth it not only in terms of sound quality, but they also get a lot better grip on your power cords. Synergistic, Oyaide, Furutech or whatever. Which one you get doesn't matter nearly as much as that you do get one.
Poser conditioners, power cords, all that stuff, yes every single one of them contributes to good sound quality. Plenty of time for that later. For now just get the darn wire in there. One run. Direct.
Make sure to install additional non-direct outlets nearby. There are all kinds of things like lights, demagnetizers, record cleaners, that need electricity but don't need to be on the system line. It is real nice to have a couple non-dedicated outlets nearby.