I am in the process of installing a ceramic tiled shower in our basement. When gathering tiling estimates, I am getting conflicting opinions. One tile layer is telling me that he can put in a rubber liner on the shower floor and bring it up on wall (waterproof wall board) at which point he'll lay the ceramic tile. Another tile layer is telling me I need a fiberglass shower pan installed by a plumber after which he'll come back and lay the ceramic tile. What would you recommend? I am more concerned about a quality job than cost. thx, tom