agreeing for this if you were just using it for media
if you wanted an actual network mount so you can store everything, you'd need to look at running SMB over the internet.
SMB is the protocol for network mounts on windows. Samba is the linux version, which came from reverse engineering SMB… and it's actually a lot better to administrate.
Though, SMB does suck with latency, so it might not do well with media, thus option 1 might just work if you're willing to use it.
using sftp is still valid for basic file transfers in these times