Need help finding a good SEARCH solution

We did a custom WPMU & BuddyPress installation for a client. They are using it for an Intranet.

They would like a SEARCH that that indexes not only the main site, but the entire network. To make matters more difficult they have requested that it also index any documents (DOCs, PDFs, etc) that have been uploaded to the site.

#1 Are there any SEARCH plugins (free or premium) that will index and return search results for an entire WPMU / BuddyPress network?

#2 Are there any SEARCH plugins (free or premium) that will index attached documents?

I know of some 3rd party apps/devices (dtSearch, Google) that may be a solution, but I would prefer not to go down that route.