Hi,
I have checked your post. I am AWS and Redhat certified and also working in IT company as server administration. I have good knowledge of Linux, window, AWS. I have deployed many WordPress websites on AWS and Lgithsail and other hosting providers and good knowledge with LAMP.
I can implement your multisite website and maintains. I will deploy new Wordpress, install free SSL lets encrypt. I will take regular backup and create a snapshot.
I have good Knowledge about the EC2 Instance, SES, Auto Scaling, Load Balancing, S3, RDS, Security group, ACL, NAT Gateway.
Thanks