Hmmm... no answers from those that finished the game already? I guess no one really pays too much attention how much leadership is gained every time you get a stone.
Anyways, here's what I have so far:
1st stone: 20 Leadership
2nd stone: 200 Leadership
3rd stone: 300 Leadership
4th stone: 400 Leadership
As for the droids, I just bought 1,200 repair droids and 800 guard droids in my initial visit to Montero. Tons of money to go around anyways, and I estimate I'll end the game with around 50,000 leadership for a level 60 warrior.
EDIT (3-4-2010):
5th stone: 500 leadership
EDIT (3-7-2010):
6th stone: 600 leadership