My three ferrets object to your implication that they bite ears and stink. We have one who will stick his cold, wet nose into your ear as a greeting, but the other two won't have anything to do with human ears. They all suggest that you've got them confused with Mike Tyson.
They also suggest that you've got them confused with those little teacup dogs that ride around in purses. They don't like to sit still for very long and would hate being carried around as an accessory. They applaud your decision to make a plushie instead of subjecting one of their brother or sister ferrets to that kind of torture.
biggrin I would suggest making one out of high quality fake fur. Ferrets are related to mink, and have the same soft fur if taken care of properly. Their bodies are very flexible so I wouldn't stuff the body too tightly, especially if you are planning to drape it around your neck. I don't have much plushie making experience, but if you need more advice on the build of a ferret, let me know.
Here are some pictures of our ferrets in action. Hopefully they will help with the design process.
http://community.webshots.com/album/501963225oiMkTH