What do you think the difference is between atomic & ionic silver? Basically there is a lot of nonsense put about about different types of cs, atomic, ionic, colloidal, nano, etc. Most of it is just fancy marketing & makes little difference, what you want is a constant current system with automatic stirrer. The best ones to my knowledge are silverpuppy & silvergen.
On the silver, you can use 4 nines but 5 nines is better.