The sterile mixing vials and bacteriostatic water can be ordered online. I have not purchased either at the drug store, but it doesn't hurt to ask the pharmacist. It might be available in your town.
i generally order supplies from formagenix.net, but checking their site just now, I see they only carry 10ml sterile vials. 20ml would be the next most common size. They do have bacteriostatic water available currently. Mentioning that because some kind of weirdness has been going on with that product for the last couple years. It is sometimes hard to source.
5 years ago, all of this stuff was a lot easier to find, but its still out there.
Hopefully someone who has purchased supplies recently will chime in with a recommendation for you.