Originally Posted by 2fast4thelaw

That is a good set up but for not much more I would recommend the following:

Alpine INA-W900 - It has Bur Brown 24Bit DACs!!! A true High-End double din unit.

JL Audio 600HD 4-channel (Add the Remote Bass Knob, its dead usefull) I feel JL HD amps are noticibly better than Alpine PDX amps.

Focal Polyglass 165 VRs or PolyKevlar K2R Power Series. These in my opinion are the very finest 2-way car audio speakers under $600.00. They will blow you away!
I can think of at least 5 sets off the top of my head that will outperform them
Zenclosures Speaker Box - JL Audio 12W3V3. In my opinion, the best SQ sub JL makes. Perfect match for the HD600 amp.
or
Stealth Enclosure by NAZAR with a JL 13TW5. This sub hits like a sledgehammer!
the w6 has a way flatter response curve if you're talking "true" sq

EQ - Audio Control EQX - I highly recommend this unit!! Its an excellent 10V pre-amp and you can really dial everything in to perfection.