Develop email list of Estate and Trust Attorneys

I need a list of estate and trust attorneys developed. I have heard it can be done using a web crawler. But I also think it could be developed by extracting emails manually from the largest law and accounting firms sites. I have never done this so I do not know the limitations. All I know is that every law firm in the US with over 50 lawyers has 1 or more attorneys who is an Estate and Trust Attorney. (Also sometime called Trust and Tax law) For example here is a page of attorneys who do it at 1 law firm. <[login to view URL]> Here is an association with a lawyer search that has 14 pages of lawyers but each has to be clicked on to see the contact information. <[login to view URL]> Here is a list of the largest law firms in the US that all have practices in this area. <[login to view URL]> <[login to view URL]> If you can figure out a way to crawl and harvest emails that would be great, if not do you have a suggestion Thank you Bob