Little Girls TTG Starfire costume for 6 yr old and fabric question

[n0+somuch]

Hi, I'm trying for the first time to make a Starfire (TTG) costume for my 6 year old. I have a simple skirt pattern shown. Howev's, I can't think of a top to make. I don't mind her belly button showing, but I'd rather her not be mistaken for pretty woman. Also, I have that thick 4-way Yaya Han fabric from Joann's. Don't have any silver yet.

1. I have a walking/even feed foot. Do I still need a non-stick foot to sew this fabric.
2. Any recommendations on a top pattern? I want one where where the bodice meets at the center of the neck and there's a simple choker style collar - not sure what that's called. This way, I can put the silver neck thing over that.
3. Any other advice? I'm so nervous. That fabric is expensive! Thanks in advance.