I am reliably informed (and experience agrees) that of developer, stop and fixer, the only one that needs protection from oxygen is the developer so save your best for that; the rest can go in any old bottle you have lying around. However, the accordion bottles are made of a somewhat oxygen-porous plastic compared to the fizzy-pop bottles so my advice would be to use pop bottles for developer and restrict the accordion bottles for use with stop (which after all is only a weak acid) and fixer.
I keep developer in the pop bottles in a cupboard so it is out of direct lighting but I am not sure how important that is - probably not very I suspect as developer is usually supplied in clear or white translucent bottles by the manufacturer...
I keep developer in the pop bottles in a cupboard so it is out of direct lighting but I am not sure how important that is - probably not very I suspect as developer is usually supplied in clear or white translucent bottles by the manufacturer...