Proper rodding should be able to accomodate a great deal of weight. What do they suggest as secure rodding for draperies of the weight you are considering? They will probably be able to help you.

One, I would not use silk as a preferred drape fabric in a tv room because the fabric will not hold up to the light and sun all day long, frequent dry cleaning is required if you have pets or children (not cheap to dry clean either), and silk is too formal a fabric for that type of room. I would choose a different type fabric that will hold up to daily wear and tear. Silk for a formal room is wonderful.

As far as blocking out light, you might want to consider floor to ceiling length and extend the width on either side of the window...does a good job blocking light and use a heavy duty traverse drape rod.