If you need a custom fit, your best bet may be Six Moon Designs. I'd recommend the Starlite. The shoulder harness can be adjusted very easily on this pack so you get a great torso fit, and Ron Moak, the owner, can give you a hip belt that fits.

In general any of the smaller gear manufacturers will go out of their way to help you. You might also look at Gossamer Gear packs or Cold Cold World. All of these guys sew.

Earlylite
http://sectionhiker.com