You can create buffs, debuffs and auras per unit. While auras contain buffs and debuffs. You could go with the normal buffs and debuffs per unit and additionally use a filter for auras to only show buffs OR debuffs OR a black/whitelist containing whatever you want to show on your auras.
Different sets aren't a good idea, imho. Just apply a custom filter.
Afaik, AuraBars can make use of filters, too. There should be no need to implement this into your layout.