I am not a business lawyer, but I have done work for an agency-client who has told me about lawyers who are "familiar" with this area, and you need to be careful - they'll ask you to put down a $5,000 retainer, tell you not NOT to form a formal business entity, and prepare a form agreement for your employees that you probably could have done yourself.

The fact is that there is nothing illegal about accepting funds for the exchange of time.  Specificaly, escort services are a legally, licensed activity, and the same rule applies with resepct to any lawyer-client relationship - a lawyer is prohibited from advising a client to break the law, and a lawyer cannot knowingly provide services that directly aid a client in breaking the law.

As a practical matter, all you need is a lawyer with business experience who is not judgmental.