You'll definitely want two of every socket, and you will want your wrenches in several different styles. Also allen sockets in metric and standard, in different lengths, and of course torx. Dont forget the inverted torx. Double down on everything under T40.
You will want a cooling system pressure test master kit, a fuel pressure kit, a compression tester that will work in petrol and diesel engines. A nice jump box is a must, JNC660 is the industry standard. Don't forget the Power Probe II with the accessory kit.