I say three 12's it's more cone area and power handling won't really matter since your only going to be 1.33 ohms instead of a full 1 ohm( power going to each woofer will roughly be the same due to impedance change).
Will play DVD's no problem while driving. No issues only needs a map update if you want to do it. GPS still works no problem. Bluetooth module included aswell.
I have a set of Rockford Fosgate T1652 Coax"s That are brand new in the box never used. I'm going to an 8" speaker now and need to sell these off. I'm looking for $75 shipped. Just PM me I need these gone quick.