@xiao: Well my suggestion to you would be, first and formost, A tailor is your VERY best friend. You have such a tiny body that when it comes to brand your kinda stuck as far as sizing goes. However I have a friend with the very same problem and a tailor took all her brand items (for a good price) and resized them for her.
Now as far as style of lolita goes...A dress with a little less flare, hemmed to your knees with a sweetheart neckline and cap sleeves will make you look taller as well as more filled out. NOW let me clarify first of all.....your height will really look lovely in a nice full skirt as well, but it will not help you look any taller. An A line style skirt will really look great on you.
If you want your chest to look larger, look for dresses with detail up top like bows, ruffles...ect.
But once again, for a perfect fit you may have to either get your dress custom made OR have it altered.
I hope this helped.
ALSO. If you liek high cut things, you might try looking at those hight waisted corset skirts? Im not sure how it would look on your body type, but it might be worth trying.