XU4 (Cloudshell2 and HC2) work solid with NextcloudPi! and were $55 for the systems - not including the HDD and the cases. Best of all is that Nacho provides easy to use docker and burnable images to just start with. And I have scripts that process all JPGs, (images of any type) into PDFs and then OCR them for better search processing. Imagemagick and ocrmypdf works fine with 8 cores.