Lawrence systems has some great videos on You-tube about setting up and configuring a secure robust network for small businesses and other organisations. Their preferred solutions include Pfsense with Professional quality devices such as the Netgate SG-1100 and Unifi Wireless Access Points. They have also reviewed and recommend Untangle Next Gen firewall as a commercially available solution. Check out their videos below.
Network setup and configuration with pfsense, Unifi and Untangle
Digital Aid Online 