It is possible to tool to make use of to drag-lower this content (html pages + css) etc of the small website? We have to do your homework around the content of couple of websites around the frequency of some key phrases. To begin with you want to parse them as html documents/files. If there's such tool that people may use, then it'll avoid wasting efforts in by hand save individuals pages.
You should use the GNU wget utility. Using the proper flags, it'll meet your requirements perfectly.
wget includes a reflecting option that might be of great interest in case your target is a reasonably simple site.
curl could have a similar option.
I trust that you're as being a good internet citizen and also have ensured (or will make certain) the people that own/run the prospective site are Comfortable with you carrying this out.
The fundamental method to it :
curl -a "Mozilla/5.0" -c /tmp/c -b /tmp/c -L -s http://domain.tld/script