It sounds like you want to be able to have the browser talk to the user's email client (i.e., click on mailto:test@test.com
and have this bit of HTML appear in the email client ready to be sent off). That won't happen with a regular browser and javascript, because the window doesn't know anything about what other programs are available or in use on the user's machine. You'll need to send the HTML to the server and have the server send the email. Also, I've been told that CSS styling for email is very difficult, so having the 'look and feel be exactly like the webpage' is going to be tougher than you probably think.
All that said, it is very doable. You just need to focus your effort on getting the HTML to the server and then deciding what library to use to send the email (depends on the language). That's only half the battle, though, as you'll need to work just as hard to style it and test it on a variety of email clients (I assume). I've never done CSS for email before, but I'm pretty sure that's what's generally involved.