How are you removing it from the 55 gal- if a siphon or pump, into a smaller container, it will probably self aearate, right?

I'm not sure you would need to re-filter it.

I have been told, and read data to support it, that you should use a 2% solution of stabilized sodium dioxide, 1 ounce per 30 gallons, which will allow for long term storage (claims are made of 5 years).
That, of course, depends on the container and it's level of cleanliness prior to filling.

I know the aerobic stabilized oxygen you mention is another much touted alternative, but it is some form of sodium chlorite or dioxide that is used in most municipal water, right?