Hi David,
Welcome to the forum.
Sounds like you are looking for Surrounds and intend to position them where Back speakers would go (towards the back of room). The correct placement for the Surround and Back speakers is like this, (with subwoofer only to show that it is a 7.1 system and not for location guidance)
So, if you place the Surround at the location meant for Back speakers, it will not be optimal. Further, using ceiling speakers for any of the surround or back speakers is a compromise and would conflict with the next quote.
Last but not the least, Surround for music should be tone matched with the Left, Right Front floor standing speakers and cabinet Center. It is generally believed that a matching bookshelf speaker from the series will best serve music needs. On the other hand, dipole speakers are considered to provide a more pleasing ambient envelope for movie watching. It is not as critical to tone match Surround and Back speakers for movies. You will need to pick a preferred setup.