I would not recommend David Clark. I have tried lots of headsets, and I do not see why David Clark headsets are priced a good $100 more than comparable headsets.
I personally recommend noice cancelling headsets. What a difference! You can get a low/medium end pair for $350-500 dollars. If you have any doubt, try a pair of noise cancelling headsets in flight. Fly the first part of the flight with the noise cancelling off, and then turn it on for the rest of the flight. You will notice a HUGE difference.