This REI Flash 55 Backpack review features a user-configurable, lightweight, internal-frame, roll-top pack.
Keeping Gear Handy on the Trail with Multi-Use Accessory and Utility Pouches
Having accessible “pockets” on your pack is useful for keeping little bits of gear handy without taking off your pack. But consider a multi-use pouch that can also be worn as a standalone fanny-style pack.