I use 800ml in 8x10 trays and keep developer for future sessions although if the next time I'm in the darkroom is a few days/weeks them I make some new stuff up. Stop bath reused unitl it starts to change colour (not until it's grape purple!) and fixer I tend to make up new every 2nd batch of developer. None of these process near there manufacturer recommended quantities so I guess I err on the cautious side of the capacities.

I would bottle your chems in anything you can wash out (I'd avoid plastic milk containers as they never seem to wash well - I think anything with a #2 recycle label is ok), just remove any labels, mark appropiately and store somewhere away from any food and drinks (maybe a different room/cupboard)