I am look at IEM systems (possibly the Shure PSM 600)

If I want to send a single mix to more than one persion, I assume I would
use one transmitter and multiple receivers set to the same frequency?

Also, In the interests if hygine, do I need to purchase seperate drivers /
earbuds for each person, or are there slieves (or gels) on the ear buds that
can be swapped for different users?

Thanks