You could probably make your own image with judicious use of wget and some scripting. It wouldn't be easy, and you would have to be careful on the spidering, and you would need to do a massive amount of cleanup when done (scripts are your friend!), but it could be done. I've done it myself for smaller sites that I wanted to keep in case they went down (which invariably they did and disappeared). Setting it up to be searchable wouldn't be easy, though - but there are tools for that as well...