Should I change my name to a nickname I want to be called or a full version of the name?

Well I'm a teen girl and my real name isn't Rory but it's what everyone calls me. I love it much more than my real name. My stepfather is going to legally adopt me and I will change my last name to his and I am going to change my first name too. My question is, do you think I should change my name to Rory since that's what I will go by or should I change it to Lorelai or Aurora since Rory can be a nickname for those? Rory is my favorite name, then Lorelai, then Aurora. Opinions? And middle name suggestions for each name please! Thanks!