To have a truly authentic steam bath or sauna bath environment, these need to be separate rooms constructed with the most appropriate materials for the application - tile for steam and wood for sauna. There are endless options for having both in one area depending on how limited your space is.
As far as adding a steam generator to a sauna room, check out the Steamy Heater Series
which has the option of introducing steam into the sauna environment while operating at a lower temperature. Call a Project Coordinator
to help you find the right solution for your home.