Not all threads get the kitty cat dance.
Good luck with your hydration issue.
Just to reiterate.
Camel backs, available possibly at Costco, Can tire, walmart, zellers, sports stores, military whole sale outfitters, possibly superstore.
Nalgene bottle, sports places, can tire, walmart
Canteen, military surplus shops.
Then theres always the option of a water bottle. Smaller ones can fit into mag holding slots on vests, but may slosh and hold very litte, they require to be refilled often on a hot day, and with out a fresh water supply handy, Water jug, paintball playfields main building, it could get a little harsh.
Also, theres also walking kits. Try your local sports retailer, lulu lemon, walking/running room for these.
http://walking.about.com/od/prpack/tp/singlepack.htm
That idea is just a proposal, you may be able to rig something up.
Numbers 3,8 and 10 arnt to bad for what you night need. You might be able to rig something up. But well nalgene bottle in an butt pack works good too.