Fan+Friend Dress Question

Hello!

Well I am a long time lurker to this come and I want to ask you a question.
The dress from fan+friend (displayed under the text), does anyone own it? If so could I would like to see it worn! Would you need another petticoat or pannier?
 And another thing, I am currently loosing alot of weight, should I wait or is easy (”easy”) to sew it in?
I am very thankful for answers!

(link for better pictures: http://www.fanplusfriend.com/servlet/the-1318/Cute-Lolita-Open-Back/Detail)
 

Wniny