You could do an Elsa with those...
Seriously now. Are you sure that your urge to change your name is not driven by certain emotions which you might not have later on in your life? If Kyra, a name chosen by youself to suit you, or at least a side of you that either exists or you wanted to exist, feels hollow and does not represent you anymore, then what verifies that the next name you choose will not share the same fate?
I understand that since you identify as a girl, a more feminine name than Ben is more fitting. Do not take these comments as me being judgmental on you. I just want to make sure this decision is not rushed, since I do not know you.
My proposal: Anastasia
Begins with A, makes a nice sound, has a meaning that conveys the concept of resurrection, and you can always shorten it to Stacy (another letter you like). Stacy sounds really cute. You can alternate between the two. The first sounds more formal, while the second is more friendly and direct.(<-perhaps not the right word).