Here's the thread from a couple months ago on potassium permanganate. I'm pretty sure that no one uses iodine as an antiseptic on wounds anymore. You can get antiseptic packets from the link Massacre provided. If you want it for disinfecting water, it needs to be in a glass vial, Doug has a source listed here on the ETS site.

As for plastic bottles, I just picked up a Coleman set of plastic bottles and other containers at Menards (big box hardware store), try Target and Walmart. Nalgene make a travel set also, you can probably find them in luggage stores too.