To this point, there has been no mention of medical supplies or medicine or ordinary items like asprin and first aid materials although I may have missed it. Once should imagine they will be in short supply and very valuable.
Additionally, I would suggest medical first aid books, including those that discuss illness, head injuries, suturing, setting broken bones, etc. Such is usually found in Wilderness Medicine books, Emergency Preparedness/Emergency Survival books, etc.
If we actually have 2-4 years as has been suggested in this forum, there would seem to be time for advanced first aid courses.
How about them KC Chiefs!
You can buy a Blackhawk Stomp kit for about 375 bucks.