How to Pick an Orthodontist with Differing Treatment Times

I am 28 years old and am looking into getting braces. I have slight crowding in the front on both top and bottom. I am Class I on the right and Class II on the left. I have issues with TMD as I clench at night. I had 3 separate consultations with different results. Would you be able to shed any light on the best way to choose an orthodontist and why treatment times vary so much? ORTHO 1: Exam: Did a visual check of teeth. Treatment: Said I was a candidate for traditional braces, Damon braces, or Invisalign with a 16-18 month treatment time. ORTHO 2: Exam: Took pictures of my face and mouth. Did a visual check of my teeth. Treatment: Said I was a canidate for Damon braces, Insignia braces, Incognito braces, or Invisalign with a 12 month treatment time for Damon and Invisalign and a 6-8 month time with Insignia. ORTHO 3: Exam: Did a very through check of teeth including measuring. Treatment: Did not discuss treatment types or times. Prefers to get impressions and x-rays first. I asked about average treatment times and was told 16-22 months (but they don't know how long it would be for me.) I would prefer to have braces for the shortest amount of time possible, but want to make sure that I "do it right." I am deciding between Ortho 2 & 3, but don't know how to make the decision. Thanks! Stephanie