I guess it would really depend on what type of home, the age of it and where it's located. Most of your older homes (prior to 1940) have a lot custom details you want to keep intact. If it's really old, and hasn't been maintained, then restoring may not be an economical solution. A lot of the homes in our area (DC Metro) are being torn down because the lots are so valuable.

Abe has given you a great answer.

Here is a place where your can find manufactureres and contractors:  http://www.thebluebook.com/

Not sure if there is such a thing but NAHB.Com would be a good starting point. 

Find a bracket that will span the columns. Drill and insertlead anchors into the brick at the correct locations for the connecting fasteners.

Check seals on doors & windows.  Replace single pane windows with newer products.  Check the attic for insulation.  Loose fill, blown in insulation is the best.  Make sure to seal any spots where air is escaping INTO the attic first.  Also make sure your attic has both adequate intake AND exhaust ventilation.  Make sure not to clog the airflow from the soffit area and the attic space by using Baffles as seen in the picture.  Check out YouTube for other great suggestions. 

I would build a stud wall and get rid of the recessed niche. Once done you will have plenty of support in securing the TV mount.