I'd ask the question of what sound does the height channel generate? if there is no bass going to that speaker, and the cross over is going to be set at 100hz or above, does it really matter having a speaker that can make sound below that point? I'd go with what aesthetically looks best.

Anthem: AVM60, Fosi DAC-Q5
Axiom: ADA1500, LFR1100 Actiive, QS8, EP500, M3, M3comp, M5