|I do have a question for you. You say above, "...and have a subscription for a VPN"|
Please explain in a little more detail.
If you're simply looking for remote access to your LAN, a VPN may be overkill for your needs. If you need a 24/7 connection from a remote site, it's possible an inexpensive VPN device may be all you need or perhaps one of your existing Linux clients could be setup as a VPN endpoint.
I'm thinking you may not need to build a server when you could simply buy a RAID capable NAS (network attached storage). This would provide redundant, central storage for all your data that would be accessible to all your clients and most have built in permissions so you could easily control who access what.
It matters not how straight the gate,
How charged with punishments the scroll,
I am the master of my fate;
I am the captain of my soul.