Obviously they'd have different tiers of the kits for each type of armor level

Canvas Kit, Velvateen Kit, Iron Kit, Bronze Kit, etc.

Cut down the number of mats needed for repair from being absolutely anything from the game to a cluster of approximately 12 or 15 kits two per level range basically.
Though with this system I'd say remove durability from accessories. Only Body, Legs, Hands, Boots and Weapon should have durability.