Internet/Proxy Server

There is a marketing firm who has 40 employees. All the employees have internet access either from the office LAN or Wireless access on their laptops. I need a proxy server which takes care of following points:
1. Control the internet usage by allowing required websites.
2. Internet access must be monitored and reported.
3. Report internet activity of employees using laptops when they are traveling.

Can somebody suggest cost effective solution for our small organization?