Disc situation is getting out of hand, where do I go from here? Kind of a nub

So I've been buying a couple external drives a year from BestBuy to house my ever expanding media collection, none of it backed up, and it's become a sprawling mess. I have six shucked drives in my HTPC, 4 more plugged into it but unshucked and on the hardwood floor (wife absolutely adores this), and another plugged into the computer I use to download stuff. I basically just fill up an external on that PC and move it up to my HTPC and go and buy a new Easystore to take its place.

I don't have the gettin' PC sharing with the rest of my network because it's running windows 7, and in my mind this protects the rest of the network (I'm probably wrong). I'd like to just get rid of the thing though and replace it with some kind of large NAS, or server, or JBOD rack?

It would also be nice to have a little bit of backup, but I don't want to sacrifice half of my space either since it's not critical data. Is SnapRAID what I should be looking at? I just need one or two extra drives for this and it backs up drives that are signaling that they're in trouble, yes?

My drive sizes range from 10 to 20TB's, all of them full, so I'll be shopping for more drives this weekend. I also have a couple of dormant CHIA drives that haven't been hooked up simply because I ran out of space on the HTPC where I used to run that.

I should add that I want to complicate things even further by getting a few security cameras.

Everything I have now is windows based. I don't mind having to buy stuff but I'd rather not have any kind of recurring fees, which means I'll probably have to do some sort of custom camera setup too. Eventually once I'm more organized I'd like to run KODI or something but it's just point and click the file on the HTPC and play in MPC for now.

I think ill probably stop at 24 drives, so a bay that could hold that many drives would probably work best for me in the long run. Any advice on the software and hardware that I should be looking at getting?