Another bath inside whower idea: factory window shower - the BEST idea! Imagine this done huge-Japanese-bathroom style with an old claw-foot tub in an oversized shower, so you could have overflowy baths in a shower the size of a small room.
like tiles on shower floor and walls of shower.check out these bathroom tiles. I think it would be good in a small bath to use same floor & wall tile. This is a great example (though I won't be tiling shower)