The cloth wire units are incredibly difficult to remove in one piece, especially given their age, so used ones will be difficult or impossible to find. I have no clue if they're still available from the dealership. The glue they use to adhere them to the roof, windshield surround, and rear, makes them very prone to tearing.
The later FZJ80s do have the one piece unit, however, I have not seen one without the sunroof cutout. Not saying they're not out there. Just very difficult to find. The other thing is the plastic molding on the newer models differs slightly from the FJ80s, where the plastic meets the headliner. There's a couple inch gap, if memory serves.
I would suggest checking into an upholstery shop to see if they can make a new headliner, using the wires. I was going to replace mine by sewing a new liner, but ended up finding a later model one piece for cheap.
Sound deadener has been done before. Usually in the later model one piece units, since they're easier to drop down. There's several threads on roof deadener. Noico, dynamite, and others are readily available options.
Food for thought on roof deadener, is the adhesive. Many will delaminate due to the heat from the vehicle parked, sitting in the sun. Research high-heat adhesive, that doesn't off-gas, for the roof.
