I wonder if there's any way you could get hold of the material used in those "Zentai" bodysuits? You can see through them to some extent, I think. They seem to be a mix of spandex and lycra.
Anyway, I think this is a totally cool and original cosplay idea from Spirited Away, which is probably my all-time favourite film! I do know what you mean about this character too, she's very idiosyncratic and oddly facinating. The outfit is totally cute as well, very 50's inspired
I love me some vintage gubbins <3