Currently using a Pioneer NEX-8201 radio, which has all the bells, and whistles that would need. As far as speakers go, I am using different speakers for each location due to this being a competitive SQ car. Everything is powered with two Focal 6.900 amps, that have door speakers bridged in order to get more power in the front door speakers. I am happy with the current set up I have, which I haven't had any problems with.
Feel free to ask me anything regarding this setup, willing to share any tips I may have.