I am sure you will receive many excellent suggestions for supplies and equipment from members of this forum. Therefore, I will take a slightly different route.
I suggest for any program to be successful it must have the inclusion of the staff. A successful Emergency Action Plan (EAP) is more likely to be looked at, as a vital component of your overall operation, if the staff helps, by brainstorming, acquiring skills and the necessary supplies, as they will have a vested interest in it’s success. A plan on paper that someone else develops is more likely to fail in a real situation. As vested members of the plan you/they would gain the advantage of diverse points of view in assembling an EAP that will work for your situation.
By developing such a plan by those vested with it’s success, you can bring in other organizations such as the local Fire/Rescue Department, Red Cross, Scouting groups to help you train and possible acquire the necessary resources for an organization of your size. It will also help those organizations know of potential needs in their response area.
Pete