I agree with all of the above. I would add the European badger has a mostly black and white pelt, where the American badger has a great lot of yellow hairs in the pelt. Pretty good article on wikipedia under 'badger." I think the stripes are significantly more striking on the European badger as well.

http://en.wikipedia.org/wiki/Badger

Just one more detail to think about, sourcing European hides from the USA over the internet is not for the faint of heart.

If I was going to get a full mask sporran I would probably get European badger. The amount of 3-D-ness you want in the face is a very personal choice, you got to go with what you like on that one.