My question always is wht do you have the needs display on the shelves . The black slat wall sounds interesting but why yhe shelves . Are you planning a TV on this wall? The room sounds huge so what is it exactly you mention stne wall where is that planned. I need pics of the space an actual to scale floor plan showing all of the windows and exactly where this wall is located . Every measurement clearly marked the drawinf on graph paper posted here in jpeg formt . Pics of all the materials you plan and the FP. All of this posted here in comments DO NOT start another post .

@Patricia Thank you. Yes, I am planning to have TV in the center of marble finish FP wall. On shelves I want to display art pieces. The inspiration picture has shelves, so going with it. My bad, room isn't 42 feet long but 32'. The family room has glass windows with beams all around the room as you can see in the below picture(i created this for look n feel).