Jessica,

Go to http://www.acainternational.org/MemberDirectory.aspx and limit your search to "attorneys"  and then select the state where the creditor is located, since that makes it less expensive for them it should mean a better deal for you. 

You will get a list of collection attorneys in that state that are ACA Members and usually specialize in this area of the law.  Keep in mind, most of them deal with volume business (hundreds of accounts from credit card companies for example) and having only one account to turn over may not interest them.  Still, many will accept individual accounts and only by calling can you know if that firm is a good fit for you.