RSS Guard seems to have support for Google Reader API, so FreshRSS is also supported. It's also a Qt application. You can also find other clients on the 3rd party clients page of FreshRSS
There are a lot of different methodes you could try. I think the easiest is to connect both systems with a (mesh)VPN like Wireguard, ZeroTier or Tailscale. Then you can simply copy stuff over using rsync -a (archive mode) with a cronjob or using special tools like Borg backup, kopia, etc
For desktop app for both I use SonixD/Feishin (crossplatform)
Both where fantastic solutions but I stuck with Navidrome as it was easier to share playlists. (As an URL for non registered users or as public playlist for all registered users)
My setup is as following:
Hypervisor: Proxmox VE
NAS: TrueNAS Scale (where all music is stored)
1 LXC container with Deemon installed that downloads music in mounted NFS share from TrueNAS
1 VM with Navidrome installed in Docker with the music folder mounted with NFS
You don't have to use such a setup, you can perfectly do this on your existing PC with Windows, MacOS or Linux with DE. Or server OS like Linux with CLI, OpenMediaVault, TrueNAS Scale or unRAID
A few months ago I bought a second hand Nvidia Shield TV (€40), flashed LineageOS on it. Very happy with the device, especially the performance.
I use Jellyfin, SmartTubeNext and some VOD TV apps from my country. I've Adguard Home on my Proxmox server (can also be a Raspberry Pi) that I use for DNS adblocking, so we can watch VOD TV without any ads. Works really well :)
We've switched to this from cable TV and my family loves it, we can watch anything we want without any ads and FREE!
Only problem (not for me) is that Netflix doesn't work on it without GAPPS.
RSS Guard seems to have support for Google Reader API, so FreshRSS is also supported. It's also a Qt application. You can also find other clients on the 3rd party clients page of FreshRSS