Personally, I am suspicious of plastic gasoline cans' permeability. I used to race motorcycles and the finicky motors would not start on gasoline if it had been stored in a plastic jug for more than 2 weeks or so...or in the plastic motorcycle gas tank, for that matter. You also had to drain the carburetor float bowl and let fresh gas in if they had been sitting more than a few days in any case. After realizing the jugs were letting my gas go "bad" (everything else ran fine), I switched to metal gas cans and never had any trouble again, even on gas stored over the winter.
Now, water-based photochemicals are a far shot from whatever volatile hydrocarbons were diffusing out of my plastic gasoline jugs back in the day, but it's enough that I wouldn't go and spend money on new gas jugs for the purpose. I figure you can do just as well for free, with so many PETE juice and pop bottles that are thrown away every day. I've looked at the Blitz plastic gas containers at Walmart (they are an attractive shape), and I can't find a recycling symbol anywhere on them, although they feel like HDPE to me.
I actually store film and paper developer stock solutions in empty wine boxen--the kind with a mylar bladder inside and a pour spout. They take up very little space, hold 5 liters, and don't let air in contact with the solution, even as you draw arbitrary doses. I can't speak to their keeping properties on any scientific grounds, but it has been working for me and you can't beat the convenience.