Tiny. Why bother with a stereo when youve got an engine that sounds like that dude.
Seriously I wouldnt go 6 X 9's in the rear if you intend on running a sub as well.
4" or 5" splits in the front. 6" 2 ways in the parcel shelf off the head unit and a 15 off a seperate amp will be ample in my opinion.
Theres really so many diffrent combinations that can be done. It all comes down to $$$ bit like an engine rebuild
Cheers