You might also want to look at Osprey and Vaude hydration packs, the various stores in our area carry them as well as the Camelbak. I do have the Luxe, but I prefer my Vaude as the pack itself is much lighter. Both hold 100 ounces, but the Vaude is easier on my neck - there is a different design in how it connects with the body. I am considering replacing the bite valve with the Camelbak version if it will fit.

You can also find good prices on eBay as well for these packs.