I like
httrack. It can be a bit complicated to set up rules sometimes, but it's very full-featured. There are several standalone gui frontends and a web interface for it. There's even a Windows version.
The standard wget downloading utility can also do recursive downloads, but I've heard it doesn't handle some situations well.
Not sure how you can achieve "searchable". You can always run grep through the files to search for text strings though, at least.
