Welcome to the forum Mathew.
Since you cannot put the TV above the fireplace, I'll suggest you the following:
Replace the 1 seater at the back of the room with the 3 seater leaving some place towards the window wall to walk up to the TV. Now, move the TV console to the center aligning it with the edge of fireplace ledge and the window wall. Place the M60's/M80's on the floor next to the TV console. Hang QS8's, one on the wall between the window and the door that exits out, and other on the fireplace brickwork towards the edge where the 3 seater is placed.
It would be a little odd that the bookshelf near the TV console will have to be approached from behind the TV, but the placement should serve your purpose.
Do you think this placement will work for you?
