Have you thought about the Pilot Avionics PA17-79 DNC ?
I bought a set about 2 months ago and am very happy with them. I did a 3.5 hour flight a few weeks ago and found they were extremely comfortable and performed flawlessly the whole flight. In fact I can say they are probably the most comfortable set I've ever used, including the newer David Clark stuff.
None of this having to buy new batteries all the time either, I just came home and plugged it into its charger for a couple of hours and it was ready to use again !
Regards
UA