I have a 14 foot tall shower wall that is a semicircular curve and covered to the ceiling with glazed ceramic tile. I would like to fill in over the tile, terxture and paint the top seven feet of the wall, and then put textured glass panels over the bottom seven feet. Can this be done? What should i use to fill in and cover the tile above? Do I prime the tile? Any specific products to use or is this just a bad idea?