How do you plan to contact them? If you're doing some type of manual outreach then just look for them manually. Search review sites and collect info manually. If you're doing it on a large scale I would first start with a few and see what type of response rates you get. Then you can adjust and scale based on the results of your testing. Having a scraper developed to collect info isn't difficult and you can also hire VA's to scour and collect manually in the beginning.
Thanks for the help. I was able to find a good bit of lawyers around my area, but not very many have bad reivews. Most have good ones, but a lot if not around 80% of them do not have reviews. Is that a good market to go after also?
Look outside of just the legal field. There are thousands of different people in your broad area, certainly some of them have poor reviews already.