i have all diamond audio in my car, components in front, 6x9 diamonds in back, diamond 400 watt 4 channel amp, and Pioneer 7800 deck. I love diamond audio, they are so incredibly dependable, a bit pricy though. When shopping for stereo though, here are the things to make sure you do:
1. If you plan on amplifying your interior speakers and doing subs, make sure to pick up a deck that has either 4 or 5 volt amp pre-outs, it will reduce the work your amp has to do to run at it's full potential.
2. When you amp, look at the RMS power ratings not the max power ratings, because those are 2 entirely diff things. RMS is constant power running to the speakers at any given time. Many amps might put out 400 watts max power for example, but really only put out 40 watts per channel RMS x 4 channels. This is why I have always stuck with Diamond Audio because all of their amps are rated to their true power ratings, and they are built to the highest of standards.
Good luck let me know if you have any more questions you want answered