Well Guys I can give you some input on this one - I am with a US aircarrier that has made available at reducedcost a very nice ANR headset - Sennheiser Model 45. It's a very good headset - very clear - does the noise cancellation thing very well - and get the one with the L/R adjustable module. That way you can tone down the ear closest to your flying partner - otherwise your headset will treat him like background noise - or you would need to use your interphone. I have the older model - so in many cases I put my earmuff closest to my FO behind my ear so I can hear him better.
You will like the experience of using one of these headsets. They also seem to have a nice overall effect as regards reducing fatigue.