Is there anywhere I can LEGALLY buy movies (new releases and old) as well as TV shows that I can download so they can be added to my Plex server?
Pretty much nothing “legal” is going to be able to be played in Plex. Any service that allows you to “buy” and download a digital copy (such as Vudu) is going to have some sort of DRM involved. Plex can not play anything that is DRM protected. Your only real options are to use a stream recorder like PlayOn (which WILL record Vudu streams) - but it burns an ID with your name and IP address at the beginning of each video, or buy the physical discs and rip them yourself (technically illegal under the DMCA, but as long as you are not uploading the rips, nobody is going to come after you).
I buy movies from Rifftrax that have zero DRM. It’s possible to find purchased movies and shows that don’t have DRM, but you will have to search for it.
