Look at their MagicDNS for this. It uses the hostname of the system along with your tailnet to allow you to do just this

Your best bet for a large storage server is going to be the Rosewill 4U cases or biting the noise/power bullet and getting a high disk density rack server like a Dell 740XD. Either route will cost about the same hardware wise. Are you moving a RAID/HBA card over or doing JBOD? if RAID/HBA keep in mind how you plan to cool the card

Check if you have a misconfigured firewall, but that torrent looks like it may just be dead

Looking at the project, the paid features are paywalled even if you spin it up yourself