Booking/Apointment calendar script with custommers frontend

Hello, I need a Booking/Apointment calendar script with custommers frontend. What I need it for my custommers to come to the website (front end), select an option on what they want to create an appointment for, then select date and time (which I am available ) enter some data (no registration is required), and confirm the appointment. The email with instructions will then be sent to that user after I approve the appointment (different for each type of appointment). If the appointment is not approved, then I want to send them a custom message from admin panel. There is allready and existing script that is very similar, but they dont have all the options that I need. I dont need the payment options, nothing will be charged to the custommers. You can check it out here : [login to view URL] What I need in the backend is to have options to create options/categories (different types of appointments and each lasts different number of minutes from 5-30 minutes on the calender). Select dates and time when I am avaiable, I want the ability to select appointment times for one day, and duplicate that days appointment times on other days (possibly by check boxes for the rest of the month). Need a screen where all custommers will be listed, and where I can aprove their bookings or disaprove. DIfferent e-mail templates will be sent to the custommer when I aprove - disaprove the booking, and different for each option they selected (category). Please tell me your ideas and plans on how would you do that. Thanks