Is there a specific type of divorce lawyer to have when your spouse is self-employed and hides money?

Discovery (production of documents) and an accountant to do tracing will be important for you. Most divorce attorneys are experienced in these matters. 

There is no specific type of divorce attorney but you should have someone with the knowledge base to understand an income stream analysis, life style analysis and also who is willing/able to work with a forensic accountant.  The attorney should also be familiar with the law, the tax returns and having dealt with other people who are in their own business. 

In general, any skilled divorce attorney who is familiar with self-employed workers can help you in the discovery process (the process of looking over financials and running down where the money is/what the marital assets are for division). Good luck!