I agree that its sometimes daunting to pick an immigration lawyer, but the 3 above highlight important considerations. 1. Experience counts. The first lawyer has worked for a federal agency for several years, and likely knows this area of the law (which is very process-oriented) quite well.
2. Organizations reflect interests and also allow special access. The other two lawyers both mention AILA - as a former member myself, I know first hand that the organization facilitated special access to the process that outside lawyers often didn't have, and had excellent internal resources.
Good luck - I would be comfortable with all three of the above.