Hi Freudianslap,
Seems that you have the kit range in order

. I think too, for all recommendations, that two zooms and a fast prime will do all the needs.
I am thinking in selling my 17-40 ang get the 16-35II; then I will leave both the 24 and 14 at home.
As I have already a good backpack, it will be what I will use. Aside water, you need room, for a a few extra layers - warmth and rain protection along some food/snacks, and some essentails.
I think the camera bags are too small and specific, unless you are willing to carry two bags, like a 20 liter backpack, and a messenger style gear bag.
As you are going in the raining season, chances to change lenses while hiking might be shaddy to say the least.
I think you will need a rain-sleeve, and better yet, carry a small rugged P&S. Invest in a quality backpack rain cover, some small water proof compression bags along with silica gel packs.
I would not take a monopod, but rather have a travel tripod. Mine actually allows to remove the center column, but would still be a very short monopod (12 inches or so)- tripod will be good for interior shots, night shots and others.
Some packs are waterproof, others require a rain cover, but in either case, I would not rely on either alone for water protection.
Choose a backpack with separate storage areas - last thing you want, is to be digging a filter from the bottom of it.
And go to a store to get fit - just because the pack looks nice, does not mean it will be confortable on you.
A good outdoor store, will load the pack with some weight, and then check the fit on you. Better yet, you can see up close, how easy is to reach/open zippers and all