Good stereo setup for an A body?

I am looking to install a new stereo for my '72 Duster. I don't want anything "crazy", just a solid sounding system. Probably looking at 6x9s in the back with a single DIN head unit, and probably a power amp. Suggestions or other ideas would be greatly appreciated!
Eliminate the head unit entirely and spend that money on a DSP(Digital Signal Processor) with built in amp instead.

Instead, download Tidal onto your smart phone for CD quality and above music streamed directly to the DSP and then to your speakers.

If you conceal the speakers, no one will know you have a very nice system by looking at the interior of your car.