Andy,
listen to Jim.
250 SSD for your OS. Keep it “lean”.
1gb M.2 for samples.
Edit: 1 tb, I’m on my phone, pita!
Conventional 7200 hd for projects.
at least one more hd for data, backups etc.
I’m not a composer who does “huge” orchestral mockups.
But I can tell you that the M.2 loads Superior Drummer Trilian Kontact “right now”.
Best money I spent last year!
You can thank me later,
T