This was a long and complicated project that both my husband and I worked on for the better part of two years. Finally, we have two packs. One is made of foam (finished in time for Dragon*Con), and the other is made of fiberglass which we molded from a wooden buck in a silicone mold (debuted at Kawa Kon). We're working on building lighting packs.
All from scratch. There's more info on the build here: http://www.gbfans.com/community/viewtopic.php?f=2&t=28672
Second Place - Expert Class - Project Comic Con 2012