Another option is to have the other party come to the International Terminal and meet you in the international departure area, which has a food court, shops, seating and some cultural displays. Arrivals areas are not set up for comfort, but rather to channel you onto the street or departing transport.
If you are all going on to downtown San Francisco, etc. the north side of the international terminal is also where the BART light rail terminal is.
Which terminal they will arrive depends on which airline they will be flying. See
here.