Under no circumstances would I purchase a supplement manufactured in China. The quality control is non-existent, and the solvents used in their manufacturing processes are often banned in the United States and Europe and may be neurotoxic. Furthermore you have no idea as to what is on the bottle or packet is actually inside the product. And if it is inside what the concentration is. I would recommend you bring your supplements with you, having obtained them with a nation that demands good manufacturing practices.
What supplements? Just a multi? What I wouldn't do is buy anything made in China -- it's the wild west out there. There are highly regulated and regarded companies and then there are the cheats and you won't know who's who. You can get anything on the internet, however, but the best is going to vary by the person and by personal preference, but without knowing which supplements you want to use we can't really help you.