The designs linked to in the OP are boring, and most are fugly! They are really the same as standard helmet designs with the color of the helmet changed to the secondary color in most cases.
The following link shows NFL team helmets with some new concepts:
http://frank151.com/check-out-the-awesome-redesigned-nfl-helmets-of-all-32-teams/
This site shows several options for each team. Some are unique and well done. The Bengals "who dey" design is really original and kinda cool.
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This Green Bay design is simply cheesy!
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I don't really care for any of the Cardinals options here, but thought this was the best of the three shown:
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