I used ACC for carpeting with the pad upgrade. Fit great. Looks great. Very happy.
For sound deadening, I used Dynamat with the foil. It provides sound deadening and the foil acts as a heat/cold barrier. I would say shop around for comparable products.
Whatever product you decide, insulate the partition between the rear seat and the trunk. This will reduce sound. Then i add some additional carpet pad under the rear seat. The mufflers are right below that so the pad helps with sound there.