I vote just run 6.5's in the front. Just find something that plays down into the 70's well. Just unplug the stock 6x9's in the back or have them run off of your headunit. And have the Sub in the back play everything lower than 70. Saves money. And i'm personally a big fan in front stage only. I prefer not having rear speakers. To me, it hurts imaging.
Also, the focals are nice. But not ultra mid bass heavy. And very bright tweets.
CDT makes a solid component.
The IDQ is a great woofer for this price range. Plays clean and has the potential to play a wide range of frequencies.