Welcome to Gaia! ::

The first one, you may want to try looking for something like a maids dress?
That looks pretty similar.
And you could get a corset/clencher that's white to add a bit more gothic-ness to it.

As for the second one, going from the second picture, maybe try looking for a white blouse that has baggy/puffy sleeves, and then just find a plain black dress.
And you could probably find a wide red belt (or maybe even a thick piece of ribbon if it came down to it?), to go round the middle.

Hope i helped slightly, not quite sure how to help any further. >.<;