Comment DEVONthink (Score 1) 211
There is a OSX application specifically written for these kind of scenario's: DEVONthink.
http://www.stevenberlinjohnson.com/movabletype/archives/000231.html
It has the Abby OCR engine built-in, a web server and an extremely smart search filter, which is able to find related documents based on metrics like keyword frequency.