From a base of no prior knowledge I too have looking into noise cancelling headsets for a self launching glider. Those Bose earbuds sound good but I figured that a noise cancelling microphone was as, if not more, important as the speakers (??) because in the ASH 26e I have flown recently I had problems making myself understood on the radio with a normal boom microphone when the engine was running.

I have been looking for a lightweight compact conventional headset and currently I am considering the Telex Airman 8 ANR headset (with a noise cancelling microphone and ANR earphones) which looks to be substantial enough to survive glider cockpit life but not too bulky. Reviews of this suggest it is not as good as full size top name headsets for professional use but hopefully enough for short term use during engine runs.