That was quick. I hope you give us a review as well. The guru looks a little small to me for what you want.
Personally I liked Jan's suggestion : "The F-Stop bags seem pretty cool and bring me to an idea: What about a dedicated hiking backpack with a separate ICU (from F-Stop for example)". I have several bags, lowepro and tamrac, they are great at protecting camera gear but are not as comfortable to carry as a good pack that is made for hiking.