My wife wants a new master-bathroom with a kick ass shower. ie: multi-head body sprays, ceiling mounted rain-head, pulsating jets, etc. (She had even tossed in the term steam but I think I may have convinced her out of that). At this point, I realize I am outside of my comfort zone ensure that I have proper water pressure/flow to the bathroom.

How can I calculate the necessary amount of pressure/flow I need, and if the city supply will even be sufficient? I presume the majority of homes run 3/4" to a bathroom like this, but is that enough? I believe I need to redo my city entrance to be a 2" to compensate for sprinklers in the new addition, so could potentially run larger pipe - I just don't know if I need to.

Can anyone point me in the right direction and/or help me understand the subtleties of these kinds of installs?