Check the front and rear brakes. I know, you said its coming from the front, but noises can transfer pretty easily and make it sound like its coming from the opposite end. If the brakes dont apply near the top of the brake pedal stroke you may have rear brake issues because the rear adjustment sets the pedal height. If that checks out, my next guess would be the upper control arm bushings. I re-read your post: Make sure the jam nuts on the lower control arms are tight as well
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