I wouldn’t use Barracudas, even for bulk storage. Spinning rust is dead; 4 and 8 TB SSDs are a thing one can afford now.
I’m assuming the Samsung 980 is an M.2 device – good choice!
32 GB of RAM is okay but not phenomenal. If your motherboard has 4 DIMM slots, you can always add another 32 GB later if you find that you run out, though. And you might not – unless you do lots of symphonic scoring together with large video edit projects, AND keep a copy of Chrome open at the same time…
I’d go with a Threadripper of some sort, or a Ryzen 5950X. For VST/cubase, “more cores is more better” much more so than the absolute peak CPU frequency. The main drawback is you do need a custom water cooling loop for those; the standard all-in-one coolers don’t have a big enough “cold plate” and thus won’t be able to cool all parts of the CPU, and then CPU may throttle itself to avoid overheating. I think someone’s come out with a Threadripper-specific All-in-one cooler, with a bigger cold plate, though, so that might be sufficient if you can find it.
Then, which interface, and what desktop monitors, and what MIDI controller/s? MOTU Ultra-Lite Mk5 is getting good reviews; I’m stuck on an old Steinberg UR-22 but if I were to upgrade today, I’d go for the mk5. If you have the desk space, the 61 or 88 key Native Instrument Kontrol keyboards are very nice, especially if you buy the Komplete package of instruments/samples. And of course as fancy monitors as you can afford – Mackie HRs, or Gelelecs, are both good choices. These will probably be with you for 25 years, as opposed to the PC, which will be replaced in 5 years, so it’s worth putting the money there.