yes, the ceiling must be properly supported while you remove this wall.
yes, you will need to install a set of kings just like in the supports for a door or window then set up a beam to span the distance and support the ceiling. Consult the span tables for the size of the beam to use as your support.
you need to realize that this could in the long run affect the movements of your home and that room and ceiling in particular. you are really getting into a rough area.
Have you also thought of resale value with this modification?