Double post! just kidding.
I'm not sure why blue is such a fault. Personally I don't like the color sooooo, on to the crops.
From the picture your dog has great ears and I wouldn't crop them. It's rare to find a good set of ears these days so I like to see those natural ears when they are set right.
But as you said, you're set on cropping the ears, so I would go with a good show crop. Short crop, no, long crop, no, medium crop yes. Long is like a Boxer or Dob. Short is like a home job, medium is done by a professional who knows how to crop ears.
For the record, I'm not against ear cropping.