I tore everything out down to the studs, replaced some of the studs, built the walls out to fit the new shower pan, and put in hardyboard and new water resistant sheet rock throughout. replaced and updated all the electrical and plumbing too, to include adding a fart fan.I'm using a pan, way easier than building my own shower floor, and three coats of mapei aquadefense in the shower and anywhere that may get wet. I might have gotten little overzealous with things, as I not only put two coats of kilz inside the walls and on the interior of the room to seal the sheetrock/wall skim. Talked senior management into approving vertical orientation on the wall tiles, I think its gonna look better and waste less. I appreciate the advice guys!