I have a 2 lb one which fits snugly, although it rides a little higher than I'd like because it's meant for children. The only problem is, it's fleece, so wearing it during the summer isn't really an option. Because of this, I bought a custom-made one for about $100 on Etsy. It's made of light cotton, and advertised as a summer vest, which I'm hoping will make it cooler. It's about 6 lbs, which is only two pounds lighter than my weighted blanket (I only weigh about 90 lbs). The weights are removable, so I can reduce the weight if it's too heavy.
About the chainmail option, I've actually worn chainmail before. It's extremely heavy, but felt really good. The chains did tend to pull my hair and pinch my skin when I moved though, so you'd have to have short hair and wear long sleeves under it. It would probably be too heavy to wear out anywhere, and would be better for providing intense pressure at home during meltdowns and the like.
_________________
"Survival is insufficient" - Seven of Nine
Diagnosed with ASD level 1 on the 10th of April, 2014
Rediagnosed with ASD level 2 on the 4th of May, 2019
Thanks to Olympiadis for my fantastic avatar!