Placing both TV and fireplace on same wall is a challenge because you will then have two focal points competing with each other unless it is a very long wall? One solution could be framed artwork designed to camoflage the TV - these can be motorized or slipped on and off. At least this way, the fireplace can be the focal point when the TV is off. Now, if it is a long wall (15' or more), you could create 2 distinct seating areas around the fireplace and TV. Would need a picture of your wall to see what best configuration would be.