shower walls

I am interested in using natural stone in my new shower, but I keep
getting conflicting advice.  Are you familiar with the thin natural
stone products, such as ThinStone, Litestone, Soterra, or Granite
Transformations?  It seems to me that these products will give me the
beauty of natural stone without the weight of 2cm slabs and without
the grout lines of granite or marble tiles.  Some contractors,
however, are telling me that natural stone is not a good choice for a
shower because of the porous nature of the material.  Then why have we
seen tile in showers for years?  They say that it will require sealing
at least every six months, and that the natural pores and fissures may
wear down or chip off.  I just don't like the look of those man-made
slabs of plastic, especially when I intend to use natural stone on my
vanity top and floor.  Must I settle for man-made in the shower?

Laura