How can I save a web page with External Resources like browsers' "save complete web page" but from command line or with node?

That is executing command /uri/of/page.html saves all js and css files referenced in page.html.

You can use wget and its recursive download ability.

http://www.gnu.org/software/wget/manual/wget.html#Recursive-Download

$ wget -r

or

$ wget --page-requisites