id say depends on how many keys you wanna have on your bunch lol if you wanna have one key then id imagine you would need
1 x key
1 x iginition barrell for said key
2/4 x door locks for key aswell (dependent if its 3 or 5 door)
1 x boot key barrell
and im guessing you would need transponder/immobiliser setup for the keys aswell, having said tht you could always swap the internals out of your own key and put it in the new key that way your electrics should still work and your just changing the barrells.
Never done it but id imagine thats a good place to start no doubt someone will have a beter answer like i say ive never done it
