InEnduringGrowStrong

I’ve not had good luck finding something that gives me the confidence to go about it

Now’s a good time to make sure you have good backups.
Knowing you can fallback to your backups helps a lot with confidence.

One this that’s really hard to replace is DDoS protection.

I use this one:
https://play.google.com/store/apps/details?id=de.orrs.deliveries

It can usually get the status of most courriers unless they’re actively hostile against API/scraping.
Worst case you can still track status manually, or open the webpage.
It doesn’t track payment, but I don’t usually have a tracking number before paying.
I think you could technically add your own custom status entry.
I keep them as active until shipped and verified after which I mark them as completed.

Works well enough for my needs.

You can use an adapter just fine.
Or use a 5.5" drive caddy, that’s just a little drawer that slides in and out.
Real question is it you have enough SATA connectors available.