What are surrogates looking for in an IP?

After years of serve pain for endometriosis, i had a "quality of life hysterectomy" and now i am in a relationship where we both want a family. What are women considering being a surrogate looking for in an IP? I know the legals, i know about the counselling and all the hoops that need to be jumped, i want to know what makes one woman decide that she has found the couple she want to help.