Contract for marketing company

Hi I need to find an appropriate contract for my marketing company. My marketing company refers clients to attorneys in US. Attorneys are prohibited by law to pay any commission to non-attorney. I need to find a contract that will allow me to legally charge commissions. I can probably charge per click, for site maintenance, phone ansvering and so on..... But I need a contract that will be flexible (price for my service will change every month based upon amount of clients i refer) and i need to make sure that I will get paid when the job is done. There are a lot of contracts for marketing companies online. I need tho find or adjust one that will allow me to charge commissions from attorneys legally. Another option that I have is to have an attorney as partner in my company on small commission. This way my company legally will be able to charge standard 25% fee. Please let me know what should I do?