Thanks guys...
I'm seriously contemplating the Thule Covert DSLR Rolltop Backpack, from the reviews I've read it seems to have the biggest normal day items section at the top but, I don't think the 100-400 will fit in the camera section. The price looks right at £120 too.
D.P I've looked at F-Stops website and everything seems to be out of stock with really long lead times
yeah, F-Stop seem to always have stock issue. i waited 6 months to get mine,t hey are just so damn good there is really nothing else out on the market that comes close to the quality and features if you are actually serious about your outdoor activities.
Still surprised they haven't managed to ramp up production. When I called them a few years a go to get my bag they said that they make 3-4 batches a year and every time they order a new production run they double or triple the quantity but they just don't keep up with demand. Its also a kind of startup so they don't have a large amount of capital to order more at one time, they have to wait for the previous batches to sell in order to finance the next batches. But I'm surprised they haven't sorted this out with more investment.