just go buy some cheap box a wine, dump the wine (if you are a wine snob like me) and then re-fill the bag after a very very good wash. i bought a 5 liter box at bevmo for $10. have stored xtol for almost a year in it and it is still perfectly good.
Just buy or get from a friend/relative a wine pouch with a faucet. Remove faucet (the hard part). Clean. Make a note of the empty weight. Fill with photo chemical; ensure no (or littel) trapped air; put back faucet.
I can buy those bags for $3/each at my local wine maker's supply... I may need to do that for my next batch of D76. That would be much easier to pour from than my accordion-jug... I'd still need to mix it in the jug though, I can't imagine stirring in a bag would be easy...
I've used Platypus bottles from Cascade Designs for years: supposedly their nylon/PE bottles are oxygen proof; not sure about the PE-only bottles. Since they were originally designed for hiking, they may be more sturdy than bottles meant to stay in a box; I've yet to have a leak and some of mine are over ten years old. However, they have a new model that contains a "silver-ion based anti-microbial" which could be problematic.
I also use wine bladders for my xtol that I bought at a wine making store. They were not very expensive. It shouldn't matter if the bag is clear or opaque, but I do store mine inside a dark basement and covered with a black plastic trash bag.