Make a PVC Pipe Alice Pack Frame
Here is an inexpensive way to make a custom alice pack frame out of pvc. Adding a bottom shelf to your pack frame will make it more versatile. The video below gives you a rough idea how to make it and some generic dimensions. Since everyones body is different you will have to play around with the dimensions and bends to get it right for you. Here is a link to survivalistboards.com giving you some more information on the subject.