Remember that all that stuff expires and needs to be inspected semi-annually, at least.Sterile packaging that lasts forever in a climate controlled cabinet does not last in a soft bag that's subject to radical temperature changes.
gloves
4x4s
tape
quality stethoscope, not the freebie Chinese piece of junk that came with the:
sphygmomanometer (blood pressure cuff)
timepiece with second hand
trauma dressings
sterile normal saline
water sterilization tablets
water containers
burn sheet
mylar emergency blankets
cravats
occlusive dressing if you don't want to learn how to improvise one from the wrapper of the trauma dressing you were using, anyway.
quality shears
PEN AND PAPER - this is the most important thing you can have. What you want to do is observe changes in pulse, respiration, and blood pressure. You need to write down what you measured and compare it to what you measured five minutes ago.
Spend fifty bucks on a basic Littmann stethoscope. It sounds the same as a cheap one when you play with it in the living room, but in a noisy environment, it makes a huge difference.
You should have a reference for the normal ranges of vital signs by age group and basic treatment guides because if you don't do it for a while, you forget things and a field reference is very useful.