Hey...

I'm petite too, 5'3", 105 on a good day with clothes on, 17" back about the same hips. My favorite overnight pack is the Gregory Z pack. I bought it after test driving many packs in a variety of sizes and price ranges. I ended up with a medium because the small compressed the nerves in my shoulders too much and made my hands numb. I have many packs of all different sizes... everything from an XS (Gregory Jug, my fave winter or heavyweight daypack), small (another gregory whose name escapes me) to medium (the Z-pack) etc. I also have a Cilogear pack as my mountain rescue pack (it is a 90L pack - huge but comfortable) which has an infinitely adjustable suspension system. On bigger packs the only thing I usually go small on is the hip belt. I tried on a Osprey pack once... they swapped the whole suspension system for a small and then we realized that it was too small to fit right. So we put the medium shoulder straps back on but kept the small hip belt... it felt nice but at 5# and change I decided it was too heavy for me. This has been a long way of saying that you need to just keep trying packs on until you find one that fits. Packs are like shoes - what works for one won't work for another because we are all shaped in different ways. The length of your back is as important as the slope of your back, and packs just fit differently. Even within brands there can be a great deal of variability.

Have fun searching!

MNS