Hayward and Green (01273 492237) have a load of headsets in stock.(and also v helpful fixing them.)
I have a lightweight Telex, but am seriously considering a noise cancelling HMEC 25 (Sennheiser). Lots of dosh, but you can rotate the earpieces so that one is off your ear. It certainly seems a nice bit of kit but I haven't used one in anger yet ! I'd be interested to know what anyone else thinks