A couple of things to look for would be:
Did the spring correctly mount on the upper rubber spring perch and lower spring perch on the shock body?
Did you go through the brake bed in procedure to ensure proper mating of pad and rotor?

You can remedy both of these by reseting spring alignment and taking the pads off and hand sanding them with 150 grid paper and scoring the rotor in a hatch configuration (bottom to top) not in a circular manner. This will reface the two surfaces enough to allow you to re due the brake/rotor bedding process.

I have a very similar suspension set up to yours and I found that this definitely helped me to eliminate the mid level brake vibrations on my car.

Hope this helps.

PE

Stock wheels? Has the front end been inspected throughout? Oversize tires? Rotor warped by uneven lug nut torque? Crap keeping the disc from seating squarely?

Normally I would go with a warped rotor. Does it get worse if you apply the brakes harder?

Turns out it was a warped rotor. My first ever brake job was on this car and when I mounted the new rotors I didn't line the holes up with those two 12mm mounting bolts that thread into the hub. Drove the distance of about 8 houses until I got it back up and found what I had done wrong. Had the rotor re-surfaced by a reliable mechanic and now the problem is gone.

Thanks for the input

Well, fourth guess. Still not bad.