Build simple twilio phone system for office

We need a basic phone system using twilio and/or other technology. We need the phone to ring to ring to the system and if the receptionist doesn't answer it should go to other representatives. If it's possible we would like to have the ability to transfer calls to other numbers. We also need for all messages to be recorded and forwarded to an email address. We also need an easy to use sms system to send and receive messages. build lists, etc.