Anyone Asked About Seating Options Before?

I am trying to sort out seating for an upcoming flight and I am wondering if contacting the Lufthansa Airlines Dulles Office is the best way to get clear information. Sometimes certain seat types sell out quickly, and I want to know what my options are before I lock anything in. If you have spoken with them about seating choices, were they able to explain what is available and whether anything might open up later? I want to hear how others handled this so I can make the right decision without stressing over it. Any insight from real experiences would be appreciated.