aftermarket stereo

Hi everyone.
I just joined as my son picked up a 77 Volare for his first car. Slant 6, auto, 2 door. Only 65000 km. Runs great but the body needs a bit of work.
Anyway, he wants to put in a new stereo. AM radio doesn't do it for him. I've never dealt much with Mopar products and from looking at the dash it seems that an adapter plate of dome sort is needed.
Any suggestions? The am/fm unit will be a modern pioneer system with 6x9s in the back.
Thanks
Jeff
Author: /6Volare