Many DSLR backpacks don't have the depth to store a DSLR with the battery grip attached but the Think Tank Photo StreetWalker HardDrive is one that fits the bill. Besides being deep enough to store a battery grip attached, the StreetWalker will fit a 70-200mm f/2.8 lens attached as well as four extra lenses and flashes, as well as a laptop up to 15 inches. (If you don't need a laptop sleeve, the similar StreetWalker Pro is a bit cheaper). Besides being able to carry around a good amount of gear, the StreetWalker is very comfortable to wear with well-padded straps and a waist belt that can also be removed. The backpack can also be upgraded with one of Think Tanks belts. The bag will fit a tripod on the exterior, and with the straps in the middle, carrying a tripod doesn't skew the weight of the bag.
The interior compartments, however, aren't divided evenly down the middle. While that cushions the shape of the camera body best, the one side is a bit narrow and all your heaviest lenses will likely be stored towards one side. The depth that allows for battery grips to be stored ready to go also makes the bag's profile a bit larger--but you can't have it both ways. That's a very minor complaint for a well-built, comfortable bag. The bag's capacity and features will run you about $230.