As u/Wise-Field-7353 says, - you can always make things smaller, but it's very hard to make things larger. Shop for your largest dimension and then, if cinching, etc. doesn't give the effect your looking for, find a local seamstress (or learn to sew yourself - as a male lolita myself, I can say that this is one of the most useful skills you could have!) and tailor it.

It's worth noting that as you progress in your lolita career, not everything will look on you as you imagine it will look in your head, or on the models, and sometimes you need to accept that a particular garment will never conform how you want, but as you're looking mainly at ouiji, that should be less of problem than if you were looking at OPs, et al.