"My two inuke 6000 units aren't really a good impedance match for the eight ultimax and I'm trying to figure out alternatives. If I stick with the inuke I'll have to buy two more any way I figure."
actually, in your case, they probably are...but yeah, two more would be required.
upwards of 2000 watts are required to get the drivers to xmax in 4 cubic foot sealed cabs.
the 6000 will sustain 1700 both channels driven before shutdown.
with 4th order low pass at 80hz, most of the time, even at 2200 "watts", the amount of current going through the driver will be such that power dissipated will be much lower than 2200 watts. so, having the extra voltage is a good thing.
power through a um18 with voltage set to produce 2200 watts into drivers dc resistance.
and it will probably be even a little less than that on the low end because of the high pass filtering in the signal chain (including the approximately 1st order highpass around 7hz in the amp itself).