Below: My Curious Gypsy Thermals. I have two of these tops: the first one I purchased was when it was re-released thanks to Youth Monument. The second thermal I purchased from ebay. One is a size small, and the other is a medium. They are very stretchy and very delicate.
There are alternatives out there- but in my research and hunting, nothing really comes that close to the original.
Below: Bella wears the Curious Gypsy Thermal in the Science class scene in Twilight.