Searching PDF Files on server

We have a client that has a large amount of pdf files on the server. They also have over 300,000 records in a database and about 1/3 of those reference a pdf file that is on the server.

So is there already built program that I can purchase that will search pdf content when a search from a form is done.

So there would be a search form. Search form would look through records in a database for the search term and or search through pdf files for the search term.

Hope this makes sence. I know there are some programs out there but haven't tried to do this before.