Thinktank range is worth checking out.
I can recommend the Retrospective range, use the 5 for my current gear, also had the 7 which would probably be ok for you.
Recently got caught out in the mother of all thunderstorms, so bad the Dutch police stopped and took us back to the police station for safety.
We were soaked through to the skin in about a minute, bag without the waterproof cover stayed dry inside, very impressed indeed
Maastricht Police were superb and friendly, gave us hot drinks and towels to dry off with.
Then took people back to their hotel or cars and in our case the station for a train back over the border to Germany
Was quite a precarious position to be in, by a river with no shelter and lightning striking the ground around us
Thunder had so much force you could feel the shockwave, came out of the blue after a pleasant morning
Here is said bag with soaked walking party, camera used had been in the bag and its not a weather resistant model