Which AWS service or resource will support this task?

Explanations:

AWS WAF (Web Application Firewall) is primarily designed to protect web applications from common web exploits. It does not support deploying third-party firewall appliances in a highly available manner.

AWS Security Hub is a security service that provides a comprehensive view of security alerts and security posture across AWS accounts. It does not facilitate the deployment of firewall appliances.

AWS Firewall Manager is a security management service that makes it easier to centralize management of firewalls across multiple accounts. However, it does not directly provide the infrastructure necessary for deploying a highly available firewall appliance.

Gateway Load Balancer is designed specifically to deploy, scale, and manage third-party virtual appliances, such as firewalls, in a highly available manner. It provides transparent network routing and scales based on demand, making it suitable for this task.