I can also recommend Lenovo ThinkCentre MiniPCs or similar brands. Those can often be found cheap when companies upgrade their Hardware. These machines are also power efficient when idling, use even less space than a laptop and the case fan is very quiet (which can be annoying with laptops under load).
I'm currently running Syncthing, Forgejo, Pihole, Grafana, a DB, Jellyfin, etc... on a M910 with an i5 (6th or 7th Gen) without problems.
I'm currently running Syncthing, Forgejo, Pihole, Grafana, a DB, Jellyfin, etc... on a M910 with an i5 (6th or 7th Gen) without problems.