I'm giving my kitchen a reface and hanging new cabinets. Being an old home i'm also running some extra outlets and switches to add a range hood, under cabinet lighting etc..Running the new wiring has required removing some sections of the drywall. Problem is the material I am removing is sort of a drywall, plaster front with a paper / foil backing, no insulation in walls, wall is an exterior kitchen wall.

What product do I use to replace the sections of old style drywall? All the building stores this product is no longer on the market. I've purchased vapor barrier enclosure covers for the outlets and switch boxes but what else should I purchase to keep moisture out. I was going pick up a product called Relectix, a thin double sided foil back insulation product that reflects radiant heat and then cover that with drywall.

Any suggestions. Thank you.