the point is that my folks (who the htpc is for) live over an hour away and remotely connect to the server. They also watch DVDs. It would be nice to simplify things for them with a single box to do it all.
If they went with a BluRay player on its own, it would add one more box to clutter the area and make it more confusing.
Yeah, I ninja-edited my response to that in while you were posting. I completely agree, give people what they want, not what you think they should have.
I also took a gander at the NUC you listed. Did you know it is a Dual core sans HT? my current CPU crushes it in benchmarks and Emby can use the OpenOMX transcoding with the APU.
Yes, none of the use-cases you listed were CPU-dependent. Transcoding would be; Plex uses quicksync but if you need to transcode in software the atom celeron is not a good choice.
SABnzbd and SFTP are rather CPU intensive. So is running VPN.
I ran sabnzbd on a celeron for years and it was fine. NZBget is much, much faster though, particularly the latest release just blows sab out of the water. SFTP is not CPU-intensive. For VPN it supports AES-NI to offload crypto so itāll get around 350Mbps, which is the max anyone gets with a single openVPN stream anyway.
so what you are saying is that I should pick up the DS918+ for the NAS and a NUC for the Emby Server/NZB?
1 Emby stream is using about 27% of the CPU.
so, based on this image, which chip would be best for the Emby server? the NUC or the NAS?
I am currently experimenting with FreeNAS in a VM.
experience wasnt great. think ill stick with linux based setups like DSM/QNAP/ASUSTOR and ubuntu/fedora/debian/cent
Yeah, FreeNAS is for ZFS and thatās about it. The UI is really terrible.
Have you seen the new UI they are working on?
Iāve seen videos of at least two UIs that were supposed to be āthe cool new thingā. So far my freenas install from a couple weeks ago still looks like ass. When they are confident enough to make the new one the default, then Iāll give it another look. 
Donāt get me wrong, it looks fancy. But it also has to be intuitive, stable and ā¦ well, it has to work. And them not putting the fancy looking one in as the default tells me that those other points are not crossed off the list yet.
I believe the new UI is supposed to come out of beta in 11.2 (later this year), but that could change of course.
I do like that it comes with netdata now.
This is kinda what has me leaning towards a DSM NAS. I wouldnt mind doing the Xplosion DSM thing but only if I knew my Ryzen 5 2400G would work right with it. I still need a board, RAM, Case with Backplane for hotswap etc. Or something along those lines.
With your drive config, FreeNAS isnāt a good option anyway. I think itās gotta be either DSM or custom LVM2.
Thereās also Unraid. It works great, doesnāt need a ton of RAM like FreeNAS, and is another solution for mismatched drive capacities.
I wouldnāt build a frankeNAS with that DSM clone. I looked over their forums and it reminded me of the tonymacx86 hackintosh forums, a horror show, everybody talking about which āloaderā theyāre using, how to safely upgrade releases, etc. Thatās fine for a toy but not a major foundational component of your network.
UnRAID is great for this kind of situation. I like FreeNAS, but I also have some hardware that will only work in BSD.
but does Unraid have the software I use?
It comes down to how well does it recover from a failure. The Appliance fails and you have to put the drives in a new Appliance or power outages and drive fails.
Most people like myself will say its great until it breaks. As long as I could mount the raid pool on Linux if needed I would be trusting.
