Have you considered using kevlar?
Its like fiberglass on steroids. It should be a noise insulator, handles heat well, relatively light. Its available in fabric, rope, and wick material.
I think a kevlar rope with an armid or fiberglass core would work rather well.
If you would like to be directed to where you can purchase this type of rope by the foot for $0.75-$4 a foot depending on the diameter from 1/4"-1" pm me.
Its sort of the space age material I would pick for trying something like this.