I had the LowePro AW200 until that 70-400 entered my life. I could carry the camera, 3 lenses, vertical grip & miscellaneous small items.
It is a sling pack which i like because i can pull it around & pull the camera out of the side loaded pocket w/o removing the pack, they sell for around $90.
I am waiting for one of the camera stores to get the 350AW to see if i can carry the 70-400 mounted in it, plus it has a tripod carrying system on it.
Grumpy