Chevignon does a brilliant duffel for men (called "Marty"). It's available from www.laredoute.co.uk for £159.

If you's prefer a top-name designer, I suggest a trip to Harvey Nicks for a look at their stock - though the spring season has just come in and duffel coats are likely to be fairly thin on the ground. A good place to research top designer collections is on www.style.com, where you can view all of the menswear shows. And have a look at Prada Sport, particularly the mid-season and Cruise stock - they'll probably have a few duffel-like options.