Linux Document Management

I'm looking for a Linux (Freeware preferred) replacement for the Paperport Document Management Software by Nuance. Wants: Scan to PDF. OCR. Simple Indexing and Searching. Data stored locally. GUI. Don't wants: Cloud Based, MySQL. Most of what I am finding in my searches are business solutions (read expensive), cloud storage and systems that require a MySQL or other database server (service?). I've started using gscan2pdf. My other want, something that will let me scan from the ADF off my HP Printer (Officejet 8600).