Hydration compatible most likely means that there's a compartment that your camelbak would fit in, along with a hole for the tubing to run through. Also, I should make clear--EMS is a store brand, so you'll have trouble getting them locally. You can order online as long as you know the stuff you want. Except for shoes.
Also, some more random thoughts that have popped into my head as I prep for my own trip. You don't need a tent. They're for three things--bugs, rain, and "protection". Which means, they don't protect you but you feel protected. It's quite nice, I think, to fall asleep staring at the stars and wake up to the sun. I suppose it depends on what little critters might come sniffing around during the night, but I've never had trouble with the porcupines and other little varmints. Tents obviously aren't doing much for bears, but I don't think you have much of those. Hmmm...maybe ignore this advice and ask a local--not sure about insects and scorpions down your way.
Two little things that I think are useful that I spent like $3 total on are a thermometer and a whistle. Get little ones that would probably be by the checkout with keychain-like rings on them and affix them to your shoulder straps somewhere around midchest level (a lot of packs have obvious places where these would go). The thermometer is obviously useful. I've never had to use my whistle, but it's good to have one accessible (which is why mine's attached to the outside of my pack).
