My top 3 right now in no order:
Grey~ Safe inside hire. Plays a 4-3 scheme with various cover schemes. Bend but don't break. Doesn't take as many risks as MP or Capers have in the past.
Kris Richards~ Former Seahawks DC who had a top 5 D twice. Again 4-3 look
Johhny Holland ~Niners ILB coach, as stated above hometown guy with Packer ties and brings Saleh's 4-3 Under/Over hybrid, Cover-3 Press scheme with him. Might be the culture fit.
Dark horse ~ Jim Haslett Titans ILB and several tours as a DC. Ties to his former team and a vet DC will get him vetted for the job.