I would buy some good ol' David Clark H10-13.4. The Bose A20s and other ANR headsets are very quiet and comfortable, but it comes at a cost. I have also found with ANR headsets that if you wear sunglasses with them and turn your head you can get severe and painful vibrations in your ear. I assume it's because the sunglasses cause a gap between your ear and the headset and the ANR tries to reduce the noise.
I probably didn't have the A20 fitted correctly on my head, but that painful vibration was enough to send me back to David Clark's PNRs.
It does depend how much you want to splash out on it, I'd get a cheap set. You might not even like flying.