Semi-OT: "Mining" Web Sites

OK, I've got a question that I'm really not sure how to go about looking for the answer to. I know that there used to be commercial products for the Mac that did this several years ago, but I think their long gone. Basically the platform the software runs on doesn't matter as long as it isn't Windows. I'm looking for a software package that can take a snapshot of a website for archival purposes and go 'x' levels deep. I want it to be able to snag stuff such as PDF documents. The problem being that every time I turn around Compaq has managed to loose even more of the old DEC hardware related documentation, and if it's still there it takes ages to find it. I've saved numerous PDF files, but I'm now wanting to do a better job of mirroring the data and preserving it. For an example of the problem good luck figuring out which old PCI video cards are supported by OpenVMS! My thought is to archive specific area's and toss them on CD-R for latter access via a web browser. So something that can update the links to a local disk structure is also needed. I'm sure I'm not the only one experiencing simular problems, or having a desire to do something like this. I'm also fairly sure this kind of a tool is of interest to this group. Zane