One set should be fine but you may have to adjust your seating die for different bullets..... I keep dummy rounds for each of the bullets I load (Seated w/ no powder or primer) to quickly set my seating die..... When setting up I crank the seating die adjustment out, raise the dummy for the bullet I'm loading in the press and then crank the seating die adjustment down until it meets resistance.....
BTW, I load with Lee dies too......