Your decision about style should be influenced by the architecture of your home and the style of your furnishings.

What do you plan to do with the raised hearth?

The shiplap on an angle is cheesy IMO and doesn't work with your home architecture.

I would remove the hearth. no shiplap, no herringbone.

a simple clean material with a simple beam mantle.

Make sure you have a plan for the floor before you remove the hearth

Is this the type of fireplace that is safe to have plywood in that position?

Thanks. I am not removing the hearth - it will be covered in quartzite. The floors have already been replaced.

Since you're retaining the raised hearth which is a more traditional style, I'd opt for a traditional look with using your quartzite as a surround, a painted transitional/traditional mantle and sheetrock above similar to the photo below. With the "heavier" presence of the raised quartzite hearth (especially if your quartzite has a lot of movement in the stone), I'd simplify and calm the other components so wouldn't choose a busy herringbone shiplap/tile or prominent rustic beam.