the discos should be in the kamino level in ep2, the pit of carkoon level in ep6 and i can't remember the third one

as for the stud counter all you have to do is get 4,000,000,000 studs which is dead easy if you have the 2x, 4x. 6x, 8x and 10x multipliers activated as they combine and you will have an overall multiplier of 3840x.

hope this helps