Welcome Red. I wanted blue, but got red, lol.
By "sliding sun visor" do you mean the interior cover on the moonroof, or the actual fold down one mounted on the headliner that folds down in front of the upper portion of the windscreen? The former is standard equipment, the latter is not, but a great idea. I don't believe they were available on Mk I or Mk II Foci. I remember them from the 60s and 70s vintage vehicles.