I've used fleece for batting with a regular cotton sheet for backing - it is super warm. flannel would be softer and more cuddly for backing, I have seen minkee or fleece used as backing too, which would also be a really cuddly backing, but its hard to keep straight. I think, more than batting, how much you quilt it would determine how stiff it is...but I'm a newbie too, so I could be wrong lol. An advantage to fleece as batting is that it doesn't need as much quilting because it won't fall apart with washing.
I would use a thin batting for a wall hanging - it gives it body for quilting, and will help to keep its shape when hanging.
I don't know where you can find camo print...but good luck! $8/yd sounds about normal to me...I like that you're sneaking snoopy in there, lol, maybe you can appliqué a camo jacket on him or something, hubby will never notice him! :lol: