I personally use the Lowepro Flipside AW (All Weather) 400 model backpack. It holds my Canon T3i, 70D, 70-200mm F4 L lens, 24-1055mm F4 L lens, 50mm 1.4 lens, Youngnuo YN-560-Three flash, as well as two sets of backup body batteries and two sets of flash rechargeable batteries all within it's main compartment. I've found this bag great for light trekking/hiking and for general travel on planes. It can fit under the seat of most planes if not all. It's a pretty awesome bag, it is light and has it's own rain cover etc...It does get heavy as you load it down and if you pack it to capacity. There are other versions which are bigger you can look into. Personally I think you would be able to fit most if not all the equipment you listed, you might not be able to fit a rain jacket in there depending on the gear you carry but a ziplocked sandwhich can fit in with your gear and the outer sides have water bottles sleeve holders.
