Molly Mac Gear sells a system that's basically a backboard with straps and loops for mollie gear clips. The premise is that you lash on stuff sacks as you see fit for your need, fewer for short trips and more for longer trips. It also allows for attaching other items in your gear; axes, hydration bladders, etc. Totally customizable.

Small cotage industry run by a very reputable individual who is commited to quality products and satisfied customers.