Pioneer is the only thing I will buy for my cars as far as headunits. If your audio needs are not cray cray, you can get VERY good results by bypassing the factory amp and just running off the headunit's built in amp. I had VERY good results doing this on the last Ford I owned and I'm actually going to pull the speakers I installed in it (CSVT that needs the engine to come out soon grrrr...) and swap them into the stang.
2000 Mustang GT Steeda build #48. Bolt ons, suspension, Novi 2000.
Just because I give you advice, doesn't mean I know more than you. Its just means I've done more stupid ****.