Create webapp snapshots for SEO

We have a website running AngularJS. In order to have the site indexed by search engines, we need a static version of it. This task is about creating a node.js/phantomjs app that can take our sitemap and save static versions of the rendered (post AngularJS processing) pages to a snapshots folder good for search engines indexing (SEO). The app will run on our own servers and should be configurable (site url, sitemap url, page ready signal [maybe a selector], timeout, etc). It will run on scheduled times (cron job) and should do it's work at once, possibly checking page modification datetime for improving performance (saving resources). The deliverables are: full source code with clear instructions for installing, configuring and executing the app. If you have a better solution for the AJAX APP INDEXING problem, we're open to new approaches (effective ones, of course). Please bid informing your approach to the problem, if you are doing it from scratch or starting from another project, and how long will it take for you to finish it.