I will provide you a consultancy report/doc which will help you to decide what cloud services will be most cost effective and suitable for your dynamic web application, be it a heavy traffic or casual users' need. My solution will give you the most out of your investments and one of the finest to deploy your application on the cloud.
You will get ideas about the following:
What servers to choose
What hosting/cloud service to select
Which virtualization platform to go for
how to deploy code with distribution among all developers
how to automate scripting, configuration deployment across multiple VPS
how to do version management
Overall, going through my proposal doc will give you some idea about your optimal infrastructure planning.