I was able to find a few bridal gown manufacture in ChaoZhou from Alibaba.com/ some of them advertise majority of their products are exported to US or Europe, and they are using the standard sizes in US like 2, 4, 6, etc. And some of them allow minimum order of 1 piece. I am wondering if we could just order from them, if I fit into a size 2 or 4. Would that be a good idea?

yes.