Sub contractor essential tools for the core 4 services. 

This is a short video showing the absolute minimum tool requirements to perform the core 4 basic services.
If you have this set up any company you sub contract for will be glad to have.
It is by no means an exhaustive list but this is almost exactly what my trainer told me to by when I first started with auto rescue.
Start with this set up if you have no idea what you need.
Don’t go cheap on a jumper box. Never use cables. Get a JnC 770 or equivalent