Me and a buddy are going on a 3 or 4 day hunt in Idaho. Packing in and setting up camp fairly deep. I have a 2800 badlands pack, I can get all my gear in the pack but have very little room for meat. My question is can I get a frame with a meat shelf and put the 2800 on the external frame? Do bags and frames have to be "made" to work together or are they interchangeable? My ignorance in this subject makes me think I can put a duffel bag or any pack on a frame but I can admit I am very limited in this subject. Is someone could explain and help me I would greatly appreciate it.