what NAS to get, trunas/synology what sizes etc

[Enquiries]

I mainly want to back up a lot of PICTURES and PDFs. try to mitigate bit-rot. have it available to be able to look at photos, pdfs, some files remotely, is the main reason I want/need one.
offload documents, and pictures so they don't take up space in my main PC. (I have 4 SDDs attached and others in the closet )