My first Dana ensigns Terra plane came with the Wet Rib front pouch option. A 5" X 8" zippered pouch with a water bottle holder on one end, attached to the lower webbing of my shoulder straps.
I used it for many years but it was made from heavy oxford pack cloth and i wanted a lighter one but was too lazy to make one.
Then I got one of the last Seek Outside light silnylon wet ribs and it's what I now have on my Osprey EXOS 58. I like the idea of carrying some weight in front as a bit of a balance to the pack on my back.
I wish Seek Outside would make these again. Having easy access to maps, compass, electrolyte powder, Steripen, GPS, water/electrolyte drink, snacks, etc. is really nice. Personally I don't like stowing a bottle in a pack mesh side pocket, irregardless whether it has a foreword angle or not.
So if you're into DIY projects just make one for yourself with all the internal pouches and pockets you desire. I recommend a "waterproof" top zipper, narrow nylon webbing and matching buckles. You'll need a QR buckle and a THREE slot ladder slide for each side. You lower webbing shoulder straps go thru the ladder slides and the vertical QR buckle strap (from the pouch) thru the side slot. It's NOT a slide found in REI.
P.S. I think Mystery Ranch still sells the "Wet Rib" front pouch. I didn't find it in their online catalog but a call to them may turn up one.