San Francisco architect Seth Boor (boorbridges.com) reused wood from this home's old roof structure and "tiled" it onto plywood backing for the look of solid core. This option is only for contained fireplaces (with a steel insert or doors).
Get the look: Seth says to shoot for wood-slat dimensions of ½ inch thick or so by 1½ to 3 inches wide. If you don't have reclaimed wood nearby, Viridian Wood Products will ship it (viridianwood.com).
DIY level: Not suitable unless you are handy with a saw. Hire a pro; serious tools are needed for cutting and installation.
Cost: Moderate (low materials cost, but labor can be $30/square foot).