Also check the knuckle and wheel bearings and the tie rod ends for play. How? Tires in the air and grab one at 6-12 o-clock and push/pull and feel for motion. Then repeat the test and 3-9 o'clock and see if there is any play. 6-12 play (only) would indicate worn knuckle bearings, 3-9 (only) may be loose tie rod ends and play on both directions may be wheel bearings or a combination of the above.

I had similar braking vibration on my old VW. A different front suspension, but I ended up replacing the ball joints, strut bearings at the top of the shocks/springs (basically like knuckle bearings) and also tightened up the steering rack and changed out the steering shaft u-joints to fix it. Basically there was just looseness in the front end and even with new brakes (first thing that was replaced) there was vibration when braking to a stop. Tightened it all up and that vibration went away.