There are reasonably good spells for this in Magic, under the school of Enchantment. You could just take solitary ceremonial magery so that you functionally can't cast spells in combat, and craft lots of limited-use items. There is a house-rule
here that adjusts the price of Temporary Enchantment for greater sanity.
I forget how Magic does on encapsulating energy in items, though, if you don't want to give them built-in powerstones.
Or, for a completely different approach, you could use modular abilities that are restricted to only grant one-use powers, and take time and such to replace to represent making the items.