I was looking at either a Fi SP415, Cadence ZRS15-1000-2, Sundown Audio Z v3 15 dual 1.. For the amp, I would get what ever would go well with the sub decided on.. Looking for some input. I have heard the Cadence subs.. I like them. I have heard alot of good things( on this board) about the Fi and sundown subs.. If you had the same budget for a sub or subs.. what would you buy? I was gonna go with a 15.. but would go with 2 12's..