I would use bsd or solaris derivative operating system with ZFS such as freenas or likes.
As for network part, exposing stuff to internet comes with inherent risk.
You can minimize it by patching and other good security practices.
REST api should be available for https access on most such solutions.
This way you can expose one port to internet and have a user with limited access.
In my opinion, for home user, ZFS provides enterprise level features at zero cost, cannot be matched with anything else.
As for speed, it all depends what do you buy hardware wise and configuration.
What do you need in what time
With ZFS filesystems (for read operations) it's all about the amount of memory for arc, followed by L2ARC on low latency ssd and mostly slow rust behind for capacity.
Hope that helps
Regards
Peasant.