@Casper I'm not very familiar with the Z4000 and before you buy breakers, maybe someone who is could confirm. According to a quick look at the Z4000 Manual, it's track outputs are 180W each.
I think one 10Amp Airpax Snapac "instant" breaker on each variable track output may be a good match with the Z4000, but not on it's Aux outputs. I believe the Aux outputs may be rated for less wattage.