Hi, new to this forum. Beginning a search for hieff speakers to match 300B SET. Want to consider room interaction/reflection issues given that the speakers sit within an alcove and radiate toward the larger living room (see attached pic). An 18" ceiling beam divides the ceilings between these two areas of the room (as well as wall that extends 3' into room at top of pic), creating a "chamber" within which the speakers sit.

Would corner horns along left-most wall work well in this room or not? What speaker designs (narrow radiation designs, front or back horn, MLTL, sealed sub w/ dipole mids, etc.) would perform WELL in this room? It would also be helpful to identify designs that I should AVOID due to poor room interaction. Thanks for input!