I agree with Glenn. Order both from a company that will give a full refund.

FWIW, your torso is a small/med from your measurement (assuming you did it correctly) and that is what matters for packs. Waist is only a consideration if hipbelt doesn't come in different sizes (i.e., permanently attached) and can't be adjusted far enough.

That said, you would want a pack a little too long than too short if given a choice.

Are you mountaineering or is there some other reason you wish to carry so much weight?