Start by removing the mantle, hearth, all the tile and mirror, leaving only the firebox.

Do you have inspiration pics of mantles you like? This way you can refer to your original wish for the style you want.

Do a thumbnail sketch of that wall, indicating all measurements:

-Width and height of wall

-Floor to bottom of firebox

-Height of firebox

-Width of firebox

-Dimension of side of firebox to edge of wall. Make sure you measure both sides. Walls are rarely exactly the same.

Do you want to leave the firebox in the same position? It probably can be moved down if you would prefer.

There are several places to purchase traditional mantles: Local fireplace suppliers, craigslist, Facebook Marketplace.

This is a surround just in the process of being installed -- before & after. We ended up lowering it and trimming the bottom. Also getting a mirror with frame for above. This is a vintage surround found on craigslist.

The stone floors are very bossy. I can see why you want to remove the stone from the fireplace. It's just too much. When doing a fireplace I don't think you want to stray too far away from the overall style of the house, regardless of your decorating style. Are you in the SW or FL? Can you show us a wider view of that room, and maybe the one visible through the doorway so we can see your style better? I wonder if you just want something less busy, like the picture below. You can't use a white-white with those floors, but what about this simple shape with a more traditional mantel, not too rustic?

Model Home · More Info

Or do you want something more ornate but without all the stone work?

Matte Venetian Plaster Walls · More Info

Heres a photo of the other side.