I went with Focals in the front and back. New 12" sub in the trunk and two Kicker amps. I did however replace the stock HU. I do suggest you consider replacing it. I don't believe sync will be that hard to reinstall. Just don't want to spend all that money on speakers and under, or over power them with the stock HU.
2011 V6 Convertible Kona Blue I Billet Grille
Ford Racing exhaust I Ford Racing M5300N Springs
Airaid CAI I Bama 91 Hybrid Tune
Koni STR.T Shocks
American Racing Bullit Chrome 18" Wheels
255/45/18 Pilot Sport A/S Plus