Honestly, I wouldn't bother. Morale is completely and totally situationally effective, which means it really isn't useful to plan around for a consistent way to win.
There are several armies that can more or less ignore morale wholesale (Tyranids, Orks). You also have armies comprised of tiny units that are essentially immune to morale as well (as you can't inflict enough casualties to make morale matter). And of course you have single-model armies (Knights) that are 100% immune to morale.
So even if you were to find the perfect combo to give you -2 or -3 to opponent's morale tests (if that is something that is out there), it would still end up being a total waste in a bunch of your games any way.