If you wanna test ZFS replication, just get two nucs or other micro formfactor PC's. Unless you don't pay the electricity bills where you're going to power the. Those are slow and power hungry
That rack SUCKS to assemble. Would have been easier if I used a drill (I should have gone out and bought one) but it took me like 3-4 hours to assemble because you have to tap each metal hole with the screw you’re using.