I agree to build your own kit, or multiple kits for different activities you do.
Something that is rarely put in a first aid kit is a head lamp. I have small cheap ones in my car kits and camping kit. yes a lot of us carry flash lights but in a pinch in the dark by yourself a head lamp would...
http://www.instructables.com/id/Cross-Bladed-Axe/
Pretty cool and would cut down on some time and energy to split wood.
Who wants to start making some?