I purchased a C&C BH2 amp from Shenzhen Audio, which arrived a week ago, a couple of weeks after placing the order.
Today I tested the AKG K-401s, the Sennheiser Momentums, PSB M4U 2s, and the AKG K-495 NCs. It worked really well and I'm very happy with the unit: the very small size, good control interface quality, and long battery life.
My only problem now is that all of my source music is MP3s and I cannot play flac on my WP8 Nokia Lumia 920 yet. Not until VLC for WP8 is released. I am tempted to buy the Colorfly source player, but I think that when VLC is released it will provide a good enough sound quality using flac.
In a competition between the Sennheiser Momentums, PSB M4U 2s, and the AKG K-495 NCs, the Momentums was an easy choice due to much better sound quality. The Momentums won't have the same isolation as the others, but even on an aircraft they will be good enough I think.
So, I'm pretty happy. Now VLC just needs to come out.