I have a 22 or 23-inch torso and don't have any trouble finding packs that fit. Almost all manufacturers make multiple sizes, with the large size usually accomodating up to that length. Only exception is daypacks where one-size-fits-most is more the norm.
I personally own packs by Gossamer Gear, Osprey, REI, Mountainsmith, and Kelty (sadly), that all fit well.
Have you ever had someone at a specialty shop fit you? Most backpacking, mountaineering, rock climbing, etc. shops have packfitters.