My wife bought the Lowepro messenger for our vacation. It is a nice simple bag - very light. But that also means not too stable if you put something compact and heavy inside. Because if it's lower shape stability the dividers do not hold that well (it they were "I" shaped it would work fine). Also do not expect to put much in the front pockets. I would say it would be too small for all the stuff you have mentioned. Just for the G2 it would fine.
I have got a (bit customized) bag from Courierware (great guys!) which could be described as larger brother to BBB2 (yes, larger - I use it with Mamiya 6 and 3 lenses, film, stuff, stuff, film .. 🙂 ). It is pretty much perfect (there is a review in the bag section which I wrote). I would say that for your needs the BBB or the slightly larger BBB2 would be just perfect. It will last a lifetime.