When I needed 7m of power cable to reach my SVS I bought some 2 x 2.5mm^2 floppy rubber cable and a removable kettle plug. Probably overkill but I was brought up on Hifi voodoo.
Rubber lays nicely flat without drawing attention to itself like stiffer PVC. I remember the kettle plug being very difficult to find. Most are moulded on these days.