i use for slightly less gear (600D ungripped with 24-105, 40, 85 1.8, 2 lensbabies, sigma 150, 580xII, cullmann nanomax 200T and batteries, cpl and stuff) a Lowepro Stealth Reporter 300AW, and it just fits.
This bag is all fine and even has a built-in raincoat
Did many walks with it, also in the mountains. if this is my only pack, i tend to replace 1-2 lenses with snacks or so
Although, fully loaded it is already quite heavy...
For your gear, id get the 400 or even 550 version.