A 5D with a Sigma 80-400 measures 10 and 1/2ins. It fits in a 300 with just over an inch to spare, in the intended manner i.e. lens in first down the middle, with spaces each side of the lens for other stuff.
It will fit in a 200 but only sideways with no useable room for anything else.
Don't know if this is any help to you, but it might give you an idea of size. I have the 200 and 300 and can only JUST fit my 40D with a Canon 70-200 in the Sligshot 300.
I've just measured the 300 and yours won't fit in that sideways either.
I've just measured my Kata 3N1-30 and you'll just get your 13ins in to that. It's not a bag to suit everybody. Although it can be used both as a backpack and a single shoulder strap [like the Lowepro], I don't think too much of the pocket/zip arrangements so try and look at one first. But for simply carrying and accessing your camera/lens it will be easy and no problem.