I think Kumik works. I've seen some Rand figures on Kumik in the Barbie uniform.
it's no use if the dress is not properly cut and sewn. I wouldn't use a non repainted Uhura Barbie head nor the Barbie body being ridiculously thin, and much too tall for the petite and somewhat curvey Uhura.
I'll wait for a Nanjin made or authorized Uhura (if that ever happens). IMHO any Uhura composite figure would harm the overall good looking ensemble of Kirk, Spock and McCoy (which I have, waiting for Scotty).
I am convinced that one day we'll have a properly made Uhura!!!