I admit, thats a tough one. The best pure camera backpacks are from Lowepro, such as their Super Trekker AW II ($390 street price; www.lowepro.com). Its big, holds a ton of camera gear, and puts everything at your fingertips. But its really not a pack thats designed to do much else except carry cameras. There really isnt a convenient place for so much as a jacket, let alone a hydration unit. Or lunch! And it sounds as if youre really doing some backcountry photography, not just schlepping around camera gear.
Osprey Atmost 65
So, Id recommend you keep adapting non-photo backpacks to your ends. Ospreys Atmost 65 ($229; www.ospreypacks.com) holds a lot (4,000 cubic inches of capacity), a great suspension, and outside pockets for camera gear for those things you want to keep handy. Add to it some REI Accessory Pockets ($15; www.rei.com) for extra lenses and other stuff. The Atmos is hydration compatible, with a pocket for a bladder and slots for the tubes, but youll need to buy your own bladder. I also like Marmots Bridger ($249; www.marmot.com), which is adapted from the Dana Designs line Marmot purchased. Its a touch smaller than the Osprey, and has two roomy vertical pockets on the outside that are perfect for lenses. Tripods tie on easily, too. Youd have to simply slip in a hydration bladder, such as an MSR DromLite ($25 for 2-liter model; www.msrcorp.com). The Bridger goes for $250.
Not a perfect solution, I admit. But I think with some planning and a few after-market additions youll get along just fine.
Get more advice from the Gear Guy as he picks this seasons top gifts in Away.coms Holiday Gift Guide. Youll probably find a few things to put on your own wish list, too.