Glad someone is thinking the same Hinata. I'm still stumped on the rest of the mane six, but give me a little bit longer, I really want to find Applejack's next as I like her a lot too.
Applejack is either going to be Sakura or Hitomi, this actually is a hard one to pinpoint. If anypony else has a thought, let me know.
http://www.first-names-meanings.com/names/name-sakura.html
or
http://www.first-names-meanings.com/names/name-HITOMI.html
I think I've found a good match for Pinkie Pie, Kimiko, description wise, sounds like out fun and loving burst-into-song earth pony.
http://www.first-names-meanings.com/names/name-KIMIKO.html