nomdeplume;
Models have been answered above, I see you are UK based, and ask about compatibility.
You will encounter 2 different types in the UK; UK NATO (Brass Plug) or US NATO (silver Plug) you can get an adapter to use one headset in each type.
One of the most comfotable headsets I use is the BOSE X - it is noise cancelling and quite expensive but, in my opinion one of the best. As for amplifying, I think as a mod more or less anything can be done as a one off. It would be worth contacting someone like Headset services at Shoreham, I would imagine they would modify a headset to order. Not the cheapest option, but one headset should last a lifetime of private flying.
If you need any more information e-mail me and I will give you contacts etc.