If you are physically fit and covering only short distances, any backpack that holds and protects your gear will do.

If you are covering longer distances and/or navigating challenging terrain you need a technical pack. The central feature of a technical pack is well-designed frame that can be adjusted to fit your torso length along with an outstanding belt that is designed to cup the shelf of the hip bones. This allows the load to be transferred to the bone structure of your hips so that the load bearing muscles of your quadriceps are doing the work. The load "feels" lighter and moves with you more naturally. Alternatively a backpack sized is small, medium, large and extra large. This, however, impacts the gear you can haul.

I did a search for "Front Loading Backpack with Adjustable Torso length" Nothing pops out as a natural choice. Of course the external frame like the Kelty Cache hauler or the like allows you the most efficient carry but are not the elegant solution for travel.

Bruce