I spent some time last year looking for dry ammonium thio and had to give up - I could not find anything in the reasonable price range and ended up buying 5L of Ilford rapid fixer from a local store. However, I still would like to have the capability of mixing my own, so if anyone has a reliable source in US, I too would love to hear.
, not US in general. All I'm saying is that I failed to find a reliable source at a good price. And I'm still looking...