SSD (and especially NVME) is not going to work for 4k video storagte, the price per GB would destroy you. NVME also brings the additional limitation of port numbers on motherboards (which most top out at only 2 or 3 ports). No one is editing 4k on SSD, at least not outside a major studio.
Cloud storage brings even more problems as even gigabit transfer rates will be an issue for 4k video. You really need 10Gb ethernet to work efficiently with it, which isn’t cheap, and you don't want to know what that will cost you per month for cloud 10gb internet, if even possible to get that speed end to end.
While a NAS or file server would work, if you are doing 4k video editing, you need more than Gigabit. So your options here are lots of drives either in the system, a 10Gb ethernet system (which will cost what your system does) or a Thunderbolt NAS. Another option is to use dual gigabit connections tied together, but I'm not aware of any reasonably priced NAS that have those so you would need to build a sever with that in mind.
Personally, I would buy a big case and a put lots of fast SATA drives shoved in it, hidden out of the way, then use longer cables and usb hubs to put your monitors, keyboard, mouse etc away from the noise or setup a dual gigabit file server. Either way, I would recommend WD Caviar Black drives as they are faster, more reliable, and not much more money than normal drives.
Organization is on you.
Create a folder for all your data, sub divide it. Stick to it religiously.
Security.. meh.. What’s in your videos that needs encryption? It makes it almost impossible to recover in a failure and slows things down.
Tape works for long term storage, however it’s NOT fast, needs quite a bit of manual labor and unless you’re checking it regularly, it’s not the simplest or most reliable system. Most companies who do use tape, also have something else as well and have a person who spends a lot of their time dedicated to maintaining it. Basically, it’s an enterprise solution, not a small business or personal one. I’ve known people who tried to use it and it failed them regularly.
The simplest and reliable system I’ve seen for backups is an online system like Backblaze or Crash Plan (which do encrypt the backup data). And for the money, they rock, but are slow if something goes wrong, you are either stuck waiting to download a ton (bandwidth caps!) or spending money and time waiting for these services to send you hard drives with the data.
Crash Plan offers a second alternative and that is to backup to another computer, using the same software. You can backup to another system on site, and/or their cloud, and/or to another location (a friend or a computer you own). I would recommend a combination of these, either local and cloud or just a nearby friend or business you trade backups with. This way if things go bad, you can simply bring the system home and restore the data without using your bandwidth and a whole lot less time.
Using this allows you a not only reliable system (Crash Plan will even warn you if it hasn’t backed up in 3 days), but also gives you an off-site backup and if you do multiple places it works as long terms as you aren’t likely to lose all three places at once allowing you to copy it to another source before others fail.
