I like metal basket muzzles and I really like Leerburg. My dog needed to have some dental work done and I needed to keep him from messing with his mouth (ANOTHER reason that muzzles are a great idea). A basket muzzle allows the dog to pant, drink, take treats (especially spray cheese in a can, which is great for training), and he can make verbal noises if he feels threatened. If he's trained to use it when you're calm, when he's calm and you're training it like you would any other skill (lots of treats, lots of patience, using a clicker), he won't be "traumatized" as some -- who don't use muzzles, I noticed -- seem to think.
Leerburg helped me fit my dog's muzzle exactly, when I called them. He's a smaller dog, so he ended up wearing a female pit bull size which is something I never would have ordered on my own, even with measurements. They were just so helpful.
I LOVE having a muzzle trained GSD. I know that if there's an emergency in my area (something like Hurricane Katrina, but even something smaller) , I can put a muzzle on him super easily and that will make it far more likely that authorities will let me take him anywhere because he is muzzled and he's CALM while he is muzzled. I muzzle-trained him for a specific medical (dental) need. But I'll muzzle train all my dogs (especially my big dogs) from here on out.
Check out Leerburg.com and do call them for help buying the right muzzle for your needs. They sell a variety of them and the ones they sell are for working dogs (so the dogs can breathe in them). They're not as inexpensive as those you'll find in pet stores, but the muzzle will last you the life of your dog (plus, probably, your next dog...)
