Moving the side board to other side under tv and purchasing bookshelves.

What do you think?

Planning on purchasing a big art piece for above fireplace and eventually redoing fireplace with stone veneer and a reclaimed wood mantle.

Which one of these chairs do you think will look best with the sofa?

Should I center sofa and chair in front of fireplace and mount tv above fireplace?
The mantle is high so I'm nervous about mounting the tv plus my husband mounted tv on wall already.

Any help is appreciated! Thank you! I've had such a hard time trying to decorate this room. And please excuse the mess in the pictures. Thanks!