Blimey Pete, you want a speaker which isn't too harsh sounding, in a hard floored room, placing the speakers in the corners & close to the rear wall.
Not impossible (maybe) but it's not going to be easy.
No rear ports, lots of toe-in,, you may get away with it, but it's going to be tricky.
Under the circumstances, Shahanian Arcs would be my latest guess. At least they can be easily moved around the room for listening sessions & then replaced close to the rear wall & corners when not in use.
Best of luck.