Do you feel this shake more in the brake pedal or the steering wheel?
If the steering wheel shakes on brake application, and the front rotors are new, my first guess would be a bad front tire(s).
If the steering wheel does not shake but the brake pedal pulsates along with a general vibration through the car, suspect the rear brakes/rotors.
In any case, I would not suspect suspension bushings, shocks, etc. if you only feel it while braking.
Hope this helps,
1980 240d 4sp
ASE Master Auto Technician
ASE Advanced Engine Performance