MSR Makes Hydration packs:
MSR Hydromedary Bag on Amazon in the $30 range
Looking to replace whole Camel back backpack and hydration bag how about KLIM!!!
http://www.amazon.com/2013-Klim-Krew...klim+crew+pack
Ogio Flight Vest (brother inlaw likes his but he said it can get warm as its wrapped around you).
http://www.amazon.com/OGIO-Mens-Flig...io+flight+vest