Besides the cosmetic changes I want to make to my setup (like a real server chassis and rack), the next changes to be made are for the purpose of improving server reliability.
First off, I want to build up my redundancies. A few months ago, a security flaw almost shutdown this service for good. That could have been prevented with a few simple security measures which have been since implemented in software, but a more sophisticated attack could potentially set us back again.
I want to purchase a redundant local storage kept separate from the main server. For reliability, I plan to get a Synology Diskstation with double the storage capacity of the actual server so that it can be mirrored for further redundancy. All together probably about $700.
Next, security can be upgraded with a hardware firewall solution. I'm not set on a product here but the ones I've looked at run around $450. A security appliance like that can intelligently route all internet traffic according to very stringent rules that I can implement, preventing unwanted connections from using brute force or sophisticated attacks to intrude on my server.
Finally, but possibly most importantly, I want an off-site backup solution. I've been looking into AWS for this. Early indications look like the space I would need would cost around $150 per year.
That's a lot, but I plan to mostly spend my own money and do this over a very long time. Again, thank you to anyone willing to support me improving this service. It means a lot.