Ram Dimensioning

I have a beelink mini pc with 16Gb DDR5. My Plan:

  • 3x14TB HDD usb disk con usb 3.3
  • 500gb nvme promox system disk
  • 2TB sata ssd disk (I want use it for ZFS caching)
  • 5TB HDD usb disk (to use for peer to peer backup area)
    Essentially a don’t want use raidz pool for heating problem, noises and electricity consume (no spin down).
    So want configure all disk a N ZFS pool of single disks.
    So want use 2x14tb for multi media, and 5tbx and 1x14Tb for PARITY SNAPRAID (allignment every hour).

my 16gb is enough to satisfy minimum requirements or an ugrade is needed? (i would waiting when 32G becoming more cheap)

Thanks
Olindo