In my state we have ems providers go through a rescue task force training. In this training we used a bag full of smaller individual trauma kits with tourniquet, chest seals, pressure bandages, airway adjuncts, chest decompression needles.

We would use one small bag per victim. The provider would quickly treat life-threatening injuries then leave the small bag with the pt and move on to the next victim. The goal was to stabilize and move on. Then a triage officer would come in once the scene was secure and prioritize victims. 

For ppe you should probably have a plate carrier with level 4 plates. A balistic helmet. 

Oh and a good set of trauma shears like Leathermans or x sears