Hi Brads
never yet found a waterproof / water resistant rucksack that actually is! You could try Go Outdoors - what I do is use an ordinary rucksack and line it with a couple of heave duty bin liners (cut down).
As for centre stands - some do and some dont! I remember when I was looking at the CBF's and found the models with ABS have centre stands, while the models without dont.
Im sure someone lese will be along shortly with suggestions on where to get one from
Have a great days riding and enjoy