Length of tent guy rope with tensioner (North Town SL6)

Does anyone have a tent they no longer use or a reasonable length of guy rope etc. to repair our tent? We lost a guy rope on holiday (we've just got back & It's like to fix this b4 it gets stored).
It needs to be around 4 metres long. An tensioner would really help as well.
Thanks for reading.
Pat (near Harrow Lane)