Putting any idea on paper is the first step in finding a solution to the many problems that need to be solved with a project that has so many limitations. The legs of the surround could only be about 4″ wide and have to wrap an outside corner touching the two side cabinets. This would limit how much detail that could be used. A claw and ball foot would be great here but maybe a little much for the other details in the room. A fluted leg with a carving at the base could work but just didn’t seem to be enough detail.
The space above the fire box is also a little complicated. To maintain a minimal heat set back on the granite, and with minimal details to create a mantle, it would require more space than was available. Then to make it tougher, the screen projected out 8″ making it impossible to display anything on the mantle.
The first thing that must be decided is to whether or not to move the screen up and if it would look better to recess it into it’s own niche. Recessing the screen also protects it from the heat of the fireplace. Since there were so many niches already, a “frame less” niche could be appropriate with the screen flush to the front. Just fortunately, we had a vent less fire box and the space above it was void of anything mechanical.
It was obvious the finish of the new mantle would have to match the two side cabinets. The coloring is a soft light brown with a darker brown glaze on maple wood. This color matching process can be a lot of trial and error to reproduce since cabinet manufacturers are not willing to give up their secret recipes.
The trend today with new homes seems to be that the builder does not want to deal with the woodworking details around the fireplace. Instead he has his framer build in all the niches he has room for and cover them all with drywall. Fortunately this time, the builder took the same details from the kitchen and installed two side cabinets with matching granite. The surround ended up with the same granite only because he needed some fire resistant margin for code. When the owners moved in, they decided the space above the fire pit was a perfect place for a flat screen entertainment system.
Design problems and challenges…
One…The screen hangs on the wall all right, but projects out on its bracket a good 8″ and looks bad from the side. Also, the heat from the fire box below will also void the systems warranty. Everything involved has heat sensitivity issues . 
Two…The owner liked the traditional look of her cabinets and wanted a traditional mantle surround to match. The biggest problem here was that there wasn’t any side space for details of a normal surround and to keep the minimum heat setback clearances from the fire box. The openings left and right were not symmetrical. It was off only an inch but an inch can be hard to camouflage.
Three…By the way…don’t spend too much money because we spent a fortune on the entertainment.
Let’s get designing some solutions.