you might have got confused about the in ceiling speakers from Dolby Atmos setups. These have ceiling speakers that add height to your sound stage. In fact you could change your layout to support a 5.1.2 setup which I think your amp will support (wont do 7.1.2 or 5.1.4 etc because it is limited to 7 channels I think).
See page 16 of this guide:
http://www.dolby.com/us/en/technologies/dolby-atmos/dolby-atmos-home-theater-installation-guidelines.pdf
For this setup you would move your bi-pole speakers back a bit so they are behind you and their diffuse sound fills in the rear sound field. Then your in ceiling can be setup as Top Middle overhead speakers which are active on Dolby Atmos encoded disks or upsampled from non atmos dolby encoded disks. Once DTS:X firmware is released shortly you can get the same for DTS as well.
anyway just an idea to consider.
Edit: made a mistake thinking it was dipole