I honestly wouldn't worry too much about finding water. Between gas stations, hotels, churches, public bathrooms, and friendliness of people in general, you'll find a way to get water for the day.
When I need some extra water hauling capacity, I just look to the ditch for some clean used bottles. Or head to a gas station and dig through the garbage. Drivers are always tossing away plastic bottles. It works and saves you a couple bucks in buying beverages.
Socks? Just makes sure to bring an extra pair or 2 in case they get wet. I wouldn't sweat the material so much as just having a few dry pairs to cycle between. 5 pairs of cheap cotton socks that are dry are warmer than 1 pair of wet, expensive wool socks
