The chaulking is available in single units but the mineral wool you need to buy a large box. One box will do about 4-6 tub's if they where the size of the one I show above.
Fire blocking is something you need to arrange yourself and have inspected. A final inspection can be failed if this step is not done or the wrong products used. Make sure your tile man, plumber or Handy Andy understand that you require this process.