I like the look of the
Tiger Skin - would match and simultaneously contrast the biscuit-coloured leather.
Another option would be
Faux Suede in "Straw" colour as it looks pretty close to the colour of the seats in it.
The previous owner of my first 740 GLE estate had glued some cord carpet on in place of the headlining material - might be an idea to give that a try as well.