The BPA scare was rather blown out of proportion. Firstly, the rat models consumed significantly more toxin than possibly for humans to do, secondly, BPA is naturally entirely leached out of plastic over a few years.
Your options are as follows:
Plastic: dozens of types of plastic, cheap as hell, and about as varied as you could ever want
SS: got the choice of mega expensive surgical grade, possible heavy metal exposure (very unlikely, but higher probability than BPA poisoning, or plastic lined SS
Wood: naturally antibacterial, but limited shapes, fragile, heavy, and just about as awkward as you can imagine.
Leather or canvas: wet sided design slowly leaks , not the best for outside a vehicle, and dry designs are..... You guessed it, lined with plastic.
Glass: about as fragile as you can get, but the least amount of flavor change to the water. Doesn't retain odors.