I would also go with an all-in-one printer, which also incorporates a scanner. Won't need to deal with installing multiple drivers or use separate connections. Plus, some all-in-ones like my Epson have a fold flat sheet-feeder for scanning multiple documents when needed.
Another advantage is that most all-in-one nowadays have wireless printing/scanning built-in via WiFi. You just need a soft or hardware router. Does not have to be connected to the net. In fact, all my scanning is done wirelessly.
Most printers/scanners come with some type of PDF software. But there are several freeware scan to PDF apps available. I've been using the free
WinScan2PDF for years. It's a portable app, so can place it anywhere on your system or on a USB flash drive. It will do both single and multipage PDF documents. Either scanned individually, or automatically via the sheet-feeder.