Originally Posted by Jan Paalman
One suggestion, depending on budget and time to get something ordered before you go - get the gear off your shoulder(s). I've had good luck with a 5DII (with grip) + 24-105mm in a Lowepro Toploader Pro 65 AW attached to my waist with a Lowepro S&F Deluxe Technical Belt. You can attach a lens case to the other side, the Lowepro Lens Case 9x13 is optimal for a 70-200mm f/4L IS with hood reversed.
Another option, less modular but also less expensive, would be a belt pack like theLowepro Inverse 200 AW. That was actually my first camera bag (which I soon outgrew) - it would fit 5DII, 24-105mm f/4L IS, 70-200 f/4L IS, and ride comfortably on your waist. It's got straps to hang a tripod on the bottom, and a pull-out rain cover, too.