You'd probably be better off with front and rear height speakers as your "Atmos" than doing what you described. This places two of the four speakers at the top of the front wall, facing forward and downward, and two at the top of the rear wall in the same configuration. Get white speakers, so they blend with the wall. Small speakers, like Gallo A'diva, Cambridge Audio Minx Min, Polk OWM3, KEF T101, Monitor Audio Radius 45 .. would be good options. Avoid big-box speakers as they would not be aesthetically pleasing.
As to the rear speakers, given the layout, everything will be a compromise of some sort. You might try the di/bi-pole option placed against the rear wall, above seated ear level but below halfway up the wall. Another option would be to get regular speakers, placed similarly, but toed-in at a 45 degree angle. Either approach may or may not work (have a return window available).
It's a VIRTUAL channel unless stated otherwise.
Last edited by RayGuy; 05-13-2019 at 11:47 AM.