What are the reasons you think AWS is your ultimate destination instead of Linode?

My advice would be to use a DevOps tool like Puppet or Chef to create recipes to make deploying new infrastructure as painless as possible. If you take it far enough, it could completely build your new infrastructure in a new datacenter, but even in its simplest form it will help you when it comes time to migrate. Spooling up more nodes in your current datacenter to handle spikes in traffic becomes much easier, too.