So today I finally was able to move the site to a new server build. I moved the site off of Amazon AWS because it was getting too pricey. The new server is built using Apache with FastCGI backend. Varnish offers a reverse proxy in front of Apache, which caches copies of the final HTML for the page, so Apache, PHP, and MySql doesn't have to be hit for every page load unless its necessary. Finally, Nginx stands in front of Varnish, which performs a bit better than Apache with large amounts of concurrent connections.
One caveat, Varnish can cause forms to break and other strange occurrences for non-static content. Please let me know if you experience issues on the site.-lunger