Possible? Americh Shower Bases

Remember the dimensions of a shower base are the distances between the outside edges of the base, not the distances between the walls (tile, glass, whatever) of the shower in which the base is installed.

If you are willing to tile the pan, Kerdi sells pre-sloped shower pans that can be cut down around the edges so that the drain lines up with your existing drain. If you also installe Kerdi board on the walls and properly tape and seal it, it will be waterproof and you can use whatever type of wall covering you like. If you are on a tight budget, Kerdi is not cheap, but its not outrageous and it works very well.

Another consideration is whether you have some flexibility in relocating the shower drain. Many drains in cement floors are installed with about a 5"x5" opening around the drain pipe so you can adjust the the final drain position to resolve minor alignment problems with the pan. However, if you already have a hole in the cement I have also found it relatively easy to chip out more cement and move the drain pipe. YMMV.

Bruce