Software for Raspberry Pi or other Microcontroller

We require a system for controlling access to a building. The unit would require a small touch screen. Ability to interface to some form of electric lock Able to take simple switch inputs from sensors to show things like doors closed, doors locked, PIR detector etc. PINs and respective valid time and dates would be stored in the system. When a user enters a PIN the system checks if valid for that time/date if it is a signal is sent to a lock to open it. PINs plus times and date information are downloaded through an Internet connection. If the Internet connection is lost the system works using the stored data. Unit reports by email when someone uses the unit successfully or a failed attempt. The unit could have an IP address or regularly poll to a Website to see if update is required. I mention Raspberry PI as a controller, simply because they are easily avaialble and cheap. I would entertain other controllers