I don't suspect that BPS is better, there still appear to be a number of pharmacological effects (https://www.ncbi.nlm.nih.gov/pubmed/27685785) it is certainly different, the structure of the molecule itself is different so it should not function in the same fashion as BPA has already been shown to work (ie it won't bind to all of the same enzymes in the same way). Perhaps it would be good to research into some non BPS plastic water bottles?
Silver is most certainly not a good alternative, there are large issues with toxicity. For something such as a water bottle this would be a concern.
I use a stainless steel water bottle personally. Iron is safe.
Thank you for your wisdom. Life sure is complicated and with so many dangers.
Maybe a genius will invent a portable way to store or extract hydrogen that can be oxidized into pure water. Future dreams...