"I would like to thank you and your staff for a wonderful conversion.  It is a pleasure to do business with someone like you and your company that offers such professionalism.  I especially want to mention Sammy Rabiei.  Sammy has been outstanding to work through the conversion and I feel that it would not have been as successful without his help.  Paul, Helga, Amir, Tammy, and the remainder of your staff have been great to work with as well."
    "Should an occasion arise that you need any type of referral, please feel free to use me as a reference.  Again, I appreciate you and all your staff."