https://marketplace.start9.com/marketplace is the list of services supported by #start9. There is also a community marketplace where folks in the community have packaged and support services to run on Start9.

For #nostr I run both a #privaterelay and #iris client on my Start9.

You should give some thought to what you plan to run as you size your server. If you will run jellyfin with lots of media you will need more disk space than 'normal' users.