Create Development Server on EC2 and Upgrade WordPress, WooCommerce and Plugins

We operate an e-commerce site running on WordPress with WooCommerce, which is hosted on a Bitnami install on Amazon EC2. There are a number of updates to the core WordPress and WooCommerce files, as well as our theme and several key plugins. We would like someone to create a development/testing server on EC2 using an exact clone of our existing site, perform the upgrades there to make sure everything goes smoothly and does not affect the many customizations we've made to the code of these files. Once we confirm everything works perfectly on the development server, we'll make the exact same upgrades to the live server. The site is a live site with 7000+ users, so it is essential that there be no/minimal downtime and everything go perfectly.