Implement a UTM appliance would best meet the requirements.
UTM refers to Unified Threat Management. This is an approach used for security management. This kind of approach can be used for the business ranging form small to medium size. The cost will also be cheaper. It helps in providing security for those products that are created by various vendors.
They help in fulfilling different security requirements as they differ for each and every organisations. It includes security solutions that helps in acting against intrusion, detecting and  preventing it,anti malware scanner, hardware firewall,etc. Thus, Implementation of an UTM appliance helps in meeting the requirements given in the scenario.