I will also vouch for the self-powered Lynx Headsets. We use them in a fleet of Stampe's and they are fantastic. no real fatigue after 6 hours flying (over the course of the day). Only niggle is having to charge them up every night.
Lynx Avionics English Site
We have 6 pairs and haven't had a single problem with any of them. You will need a helmet mind, as the fit isn't solid enough to take a slow roll or any negative G.