makes them, but they're obviously not authenic Japanese uniforms. Also, I think www.j-list.com
(not sure of the url) sells them... and I think Asahi Japan does as well. Try searching google for more webpages.
If you are looking for authentic Japanese, chances are it won't be cheap - because they aren't. They're high quality pieces, even if it is just a uniform. The tops are between $100-$200, and the skirt/jumper the same. Many people cheat and just buy the top, and find a matching skirt from a uniform place in the US online (I forgot the name of it now). Another place to try is yahoo Japan auctions - sometimes, people auction off their old uniforms. You do need to use a service that will bid for you, though, because you don't have an address in Japan (I assume).
Good luck with everything.