The price stinks but you can buy direct from WD's store. 24TB is orderable too, but not shipping yet ("1-2 weeks" it says).

At least with WD there's a wear leveling seek every 5 seconds when the heads aren't parked. That's the clicking noise I mean.

I'm a WD user, but I like head parking. It reduces power consumption and it's safer if the drive gets bumped. And it stops the clicking noise. Only downside is a small delay when the heads unpark.