You may also need a USB cable as well. Often one is included it kits, but not always if he PCB was purchased separately.
Also, certain tools will be required. Small technical screwdriver kits are handy. Soldering kits if you're not using a hotswap PCB. Tweezers might also be helpful in some situations. A small tube of dialectic grease if you want to put a bit of lube on your stabilizers.
Im just a custom keyboard kit newbie too, so I imagine many others here can make more suggestions.