I've used Clarity Aloft with custom ear molds for many years now. I've used them in various Boeing aircraft(both pax and freighter), but not the 767. They work great for me. No batteries to change, no worries about batteries dying(such as the Bose QC series which when the battery dies the headset quits working and you can't hear ATC), no clamp on your head, etc..

FWIW, I use a 15 year old Bose X in GA airplanes. They are too large to carry to work, and I don't want to wear them for 8 hours at a stretch either.

For custom ear molds, I use Avery Sound.