Your choices are to have an electrician install outlets near the speakers, vs. poke holes in the wall to run an extension cord behind the wall, vs. use a mounting of some type to attach the cord and the extension cord to the ceiling and wall to run it wherever you want it to go.
I haven’t tackled ceiling mounted speakers yet, but did have to wire ceiling mounted projector and powered screen, and chose to just run the cords along the surfaces of the ceiling and wall. Not neat looking, but I really wanted to avoid the dust from cutting wallboard, and then having to patch and paint the whole room.
Also, my wife was frustrated at first with the number of remotes required to control the room. By using triggered outlet strips, where turning on or off one device (in my case the projector) activates or deactivates the several additional outlets in the strip, everything can be turned on or off with just one button push. I had to cascade several strips together to cover all the speakers, AVR, Blu-ray player, Apple TV, etc., but it works well enough that she enjoys using the room now.