Build AWS test platform

Need to build a magento test infrastructure as a fact finding precursor to moving a Magento store from dedicated to AWS cloud. Knowledge of Magento - particularly optimising performance is a must. Any generic responses will not be pursued - please address the specification in your response. Want an architecture based on 3x [login to view URL] servers, load balancer, single-AZ [login to view URL] RDS instance, S3/Route53, aws code commit. Then need to set up autoscaling where required and load test to 10,000 simultaneous users (not simultaneous requests). Autoscaling should then drop back down to initial architecture. Outputs from the test should be: monthly price to run test infrastructure taking into account all AWS services used and data/in out etc. price per day to run at 10,000 simultaneous users and map of infrastrcucture when running at scale. Time required to autoscale from base infrastructure to 10,000 infrastructure. Advantages/costs of using opsworks to build infrastructure. On successful completion, I would expect to use the work done in this step to feed into a new project to build a production environment as well as a retainer to manage same and deal with issues, on a long term basis.