Node.JS get external web page size with all assets

I'm looking for a way to evaluate page loading time from inside node server application.

A user specifies URL of the web page and the server should follow all redirects, download all html/css/js/images and return total size (gzipped if they are gzipped) of the web-page. Ideally, size of images should be counted separately. There should also be a way to emulate mobile devices and, ideally, different browsers.

I've looked at http://ift.tt/1co2AZK but unfortunately they have an opened bug http://ift.tt/1DkxuMB which says that content size is not properly measured.

Are there any other ways?