Upgrading phono cable in Marantz 6300

Hi folks,
My vintage Marantz 6300 is my restoration project; it needs a new RCA phono cable, which I'm interested in upgrading. Do you experts have any suggestions on my options here: any recommendations on a cable, and whether upgrading one on this TT is possible? Any guidance about cables and companies would be appreciated.

It's fitting into an older mid-fi system: Arcam Alpha 9 amps, bi-amped with B&W805N speakers; all fed by a Furman reference power conditioner and Kimber Kable interconnects and speaker cable.

So, that's the background. Again, any information would be appreciated.