Accommodation reservation system

Online Booking System and Payment processing. I am looking for someone to take on a Holiday booking system and payment processing task, i am not a programmer but rather a designer, so it will need to be done in such a way that i can integrate the programming into any site. I will design the sites and will need to integrate this as easy as [login to view URL] i would assume that the best way would be for me to be able to add <!--include--> files where the relevant data will go. Payment gateways will most likely be Paypal and Offline CC processing. Which means SSL will be involved. I will also need somewhere to change settings as the programming will be used over and over, so certain settings that are unique to each site will need to be changes on one location and not in many different files. Also take note that the booking system will need to have a calendar that once a reservation has been made the dates booked are blocked out from the calendar, remember that the Administartor will also need an admin area to control bookings over the phone, aswell as freeing up dates if any cancellations. If any more info is required i will add this in.