The volume is around 35l, I will try to remember to post actual dimensions.
The green x-pac is lighter weight then the gray. The gray is pretty burly fabric.
The foam is a microcell foam.
The stitching does go through the foam.
The first pack I made completely from scratch I was not able to stitch through the foam and I had problems with the foam shifting within the strap. Now I prefer to lock the foam in place with stitching.
I have an industrial needle feed/ walking foot machine. It sews through anything put under its foot. The pack is sewn with size 92 thread.
I will post the other pics I have tomorrow, unfortunately I mailed it off today to my sister so I can't get more pics.
I made a similar pack as a prototype, out of 500d cordura. The prototype I sized as a medium for me, my sisters is a small. If you wanted a specific pic I could take one of my prototype and post it.
I have been experimenting with a removable frame sheet and aluminum stay system, to work with the bivy pad. I posted my initial trial in a different thread but here is one pic.
I love sewing gear!