I'm looking for a nice camera back pack which I can use when I go for walking trips.

I'm currently eyeing the Lowepro Rover Plus. Its got a top section for your personal effects and a bottom section for your gear. Comes with a nifty tripod holder as well! This bag is really really nice.

However, It doesn't have a slot for a hydration system(camel bag) unless I put it in the top section which isn't really ideal.

Yes, I'm a compartmentalization junky.

So my question is, does a bag like the Rover Plus with side pockets which are hydration system compatible exists?