I am 6'3" and my son is 6'4". Our torso lengths are 24" and 25", respectively. I have not been able to locate an external frame pack for any thing greater than a 23" torso. Who makes backpacks long enough for tall men? How critical is the torso lenth fit, as far as an inch or 2?

In case you are wondering why an external frame, we will be hiking on established trails in the western U.S. and I want the air flow around my back.

Thanks for any advice.