Dude~,
I converted my headset (Peltor) to ANR about five years ago, using a Headsets Inc kit I bought from
Adams Aviation, and am very pleased with the result.
If you don't feel up to a DIY job, then Adams will do it for you, or you could use the services of Richard Holder, who a number of people speak highly of. I don't have his contact details to hand, but if you wander over to
The Dark Side, and run a search on his name you should find them.
Brooklands