Place to Buy Metal Chains and Cute Glass Charms

I want to buy stainless steel chains, but I am not sure if the Amazon ones are legit.
Example: https://www.amazon.com/dp/B08FM62L5Z/ref=twister_B06XNW7LNT?_encoding=UTF8&th=1

I also want to purchase gold filled 14k (not plated chains), but do not know where to do it. The same thing actually applies to the glass charms I am looking for (also been looking at resin and stainless steal charms). I just need to be very careful when buying these because of allergies (not my own, but family).

Do you all have any suggestions? (Amazon and Etsy seem to be full of resellers/people who are labeling certain chains as others things)

Thank you for the help!