Reply to Mobile setup question, seeking opinions

Ok, so i'm currently in the process of buying a 2.2 setup for some sound reinforcement and some mobile djing.
I've already settled with behringer b1800ds as subs, now i don't want to go over budget, so my options gor tops are two: either behringer's own b215 (15" bass driver) or EV's zlx12s.
Obviously the SQ will be better with EVs.
Now the question is: will 12 tops go well with 18 subs, or should i switch over to 15 subs to gain a little punch that the 12" tops may lack?