Speaker locations and Amp selection

[Timanator]

I am redoing the interior of my coup
I plan to eliminate the rear seats and use ply wood there and mount an Amp to it. I want a really good rock'n roll system, what kind of speakers and amp should I get?
I also want to install tweets in the little boxes that houses the seat belt mechanism in the back above the seats, what kit do I need to do this, also what should I install in the stock locations?

Welcome Power!!!!