A super tool kit can be obtained from Valerie who works in the Maintenance Center in Vault City, who will give you a quest to obtain pliers and a wrench with the super tool kit as its reward.
Pliers are easily found throughout the game, including in Skeeter's workshop, and can also be used to aid in repair checks. Like the super tool kit, it is not unique, but more common than the kit.
A wrench is found outside Vault City by completing the Mr. Nixon doll sub-quest for the crying child south of the medical clinic, also outside of Vault City. This can be done by finding the doll behind the Spitoon, Cassidy's bar. Then, listen to the child to find the location of a wrench. Like the pliers, it is not unique and fairly common.
If the player character is already a citizen, both tools are available in a storage room in the vault.