So here is a listing of the tools and devices that I personally use and recommend. This will range from soldering tools to meters and scopes. In the spirit of full disclosure, where possible, I will link to the products using affiliate links. (If I am gonna recommend something, why not try to get a piece of the pie?)
These crimpers include a few sets of jaws and a nice wire stripper as well. Will pretty much handle all the different kinds of crimp pins, sockets, and connectors that you are likely to encounter when working on arcade games and pinball machines. The little soldering kit has a decent grounded iron in it, includes some additional tips and a vacuum solder puller, and the case has room to drop in a few extra items like flux, braid, cleaner, etc. The case travels well and is good to have around as a field service kit, which is how I use it, and it beats lugging around my entire soldering station.