So far i've only ever ordered from bodyline, so thought I'd venture further afield. I love love love sailor dresses, and am very tempted by this one:

I'm not sure whether to go for a medium or a large. I have a 32a bust, 28 inch waist, hips are about 38/39 inches, and I'm 5ft 8, so pear shaped and petite around the bust. Here are the measurements:
M 88cm 72cm 92cm
L 92cm 76cm 94cm
Theoretically the medium should fit, but it does suggest on qutieland that you should pick a size bigger? But I'm worried that the large will be too big, especially around the chest. Any advice would be greatly appreciated... and if you DO NOT recommend this dress, please do say so too!
On another note - there seems to be a few shopping services that can be used to purchase from taobao stores. Qutieland does look pretty good to me, and gives very clear descriptions of the items... but would people say this is the best option? I'm based in the uk.
Thanks for reading :)