I should have expected to be asked who to trust for eclipse glasses, and sure enough, I have been.
Anything from Lunt Solar Systems will be a safe choice. Amazon carries their products, and I'm sure you can order from them through other venues as well:
https://www.amazon.com/s?ie=UTF8&me=A1TBTTA27ANO5R&page=1
For a longer list of vendors, look at
https://eclipse.aas.org/resources/solar-filters