Ok, stop. STOP. THESE PINS ARE STUPID CUTE. MAYBE EVEN TOO CUTE. So you need to get them both. They just ooze cute. Plus, they are designed by Katrina, who is also in the band. That's pretty darn cool.
You can get them separately, but WHY. Get both for cheaper! They also come with a- you guessed it- cute backing card that you can stick your pins through and display it for all your cute friends.