Check this out EmptyNest,
Calming the Senses with weighted blankets.
How awful that it takes so long to get answers. Some things haven't changed in years. Took us years here actually. Many, many years.
Regarding the vests... obviously you and your daughter have been reading a lot. Temple Grandin is the person I would like to suggest researching information regarding weighted vests. Also check on Sensory Integration sites. You might find more info. there regarding the weighted vests.
You could perhaps make your own? I'm not in the USA so I have no idea of the cost of buying something like that there.
Let us know how you're getting on there.