First off i think bella swan is a great and unique idea for halloween, but i think u should wear the dress cuz bella wouldn't wear a new moon shirt. LOL. so i think u should wear the dress. Also about the shoes if ur going to wear the new moon tee then u should wear the converse if ur going to go with the dress idea i think u should wear flats! (anycolour)
HAPPY HALLOWEEN
Hope this helps.