I am unaware of a form letter. You should explain how the incident affected you, detail your financial loss with supporting documents, and hat you want to see happen. The victim assistant in the prosecutors should be able to assist you. Good luck.
My response to your question is a generic response and should not be construed as controlling to your case. I can not effectively advise about your case without knowing all the facts. Additionally, my response does not create an attorney-client relationship. You can contact my office to schedule an appointment if you would like to have me represent you.
I would recommend that you contact the victim services representative at the prosecutor's office. Under Arizona law you are guaranteed victim's rights under the Arizona Constitution, including being consulted on any plea agreement or issues of restitution. A victim services representative should be able to assist you in gathering which information is relevant to be presented to the court.