Firewalls

we have to design a firewall for a company where this system has foll... features: 1)list of blocked sites (it should block people from accessing these sites) 2)list of accepted sites 3)should monitor data packets comin in and out of the organisation please suggest tools that can be used to design firewall systems and some source on the internet where we can get those tools. and please help us on how to get along with this project.