I would stock up on screwdrivers, as those disappear, and I wouldn’t be afraid of picking up a couple of cordless ones, as those can make a long day much shorter if you’re running a lot of screws in (just start them by hand if possible so you don’t crossthread anything). A drill is handy, but a cordless screwdriver is much lighter, easier to wield for an entire day, and easier to maneuver around racks.
You have a lot of things i would suggest on your list already, a good set of wire strippers and good crimping tools. More:
- A good punchdown tool
- A rubber mallet and/or non-marring hammer
- At least two pair of vice grips
- One mid-sized adjustable wrench
- Maybe a pair of 8-10” Channellocks
You can get everything I said there for <$30 at most hardware stores, and if/when you ever need them you won’t be kicking yourself for not having them (ever have a rack/rail bent for whatever reason and no way to get it back? Vicegrips/channellocks Ever tried to tighten a loose castor on <thing x> and no way to do it? Adjustable wrench. Ever had something that just barely didn’t fit? Mallets can help :))
The biggest thing I see people skimp on is storage. You stock up with all this great stuff, now where are you going to put it? I suggest more than a cabinet with tupperware containers; a decent set of mid-sized toolboxes (17”-26”) can help you bring the tools to where you need them. A decent rolling workstation can provide a surface to work off of, storage for tools, and the convenience of portability, and in most cases, the security of a metal cabinet that can be locked.