The Alpine CDA-9833 (9835 is the same thing with a blingin' display) is a really nice head unit. I am using it to drive the speakers directly in my Miata. I really like two things about it. It has a built in digital crossover, so you don't need an external crossover circuit between the woofer and tweeter. And it has "time correction", an adjustable digital delay for each output to adjust the apparent distance from each speaker to the listening position. I did not expect it to be nearly as effective as it actually is. The adjustment is very sensitive...unfortunately, a "compromise" setting to give the driver and passenger symmetric delays doesn't work.
It has four powered channels, plus two more for an external amp.
I get great sound from some fairly inexpensive speakers in my Miata. $400 for the head unit, about $120 for the speakers. They are individual components that I picked out myself specifically for this application, not a kit. People are amazed at the deep palpable bass I can get with door speakers. But then, most cars don't have cutouts that will fit 8" speakers in the doors...