Car Audio in Early-A bodies?
For my 70 Dart I have a Clarion navigation head unit and MB Quart 6x9 component speakers for the rear deck. I will mount the Alpine amp in the trunk and it will push 150 watts rms to the 6x9's.
This should sound really decent in the dart.
I've been doing stereo sales and installations for 17 years and this setup will prove to be very nice in the Dart without spending way too much money. Though I would normally run four speakers and a sub in most of my own vehicles, but this is the route I took with this particular car.
In your car I would stay away from putting any speakers in the dash and simply start with a decent set of 6x9 speakers in the rear deck. Hook that up to a nice CD player with aux inputs for iPod and mp3 memory device. This will also allow for a Sirius setup as well. If you wanted it to play louder and cleaner at a higher volume then I would add an amp to the system.
Oh yeah hide the head unit in the glove box or stick it under the dash. Many come with remotes so you don't always have to reach to turn up the volume.
One other thought is using a Kicker volume control and running a iPod or mp3 player through that. It's a small unit that can be hidden anywhere. It has two volume controls that you could hide under the dash or drivers seat. This would require an amplifier to be used and I would run with the same speaker configuration.
That's my opinion anyway. I could get this stuff for you and get everything at a really good price. The only problem I see with that is you would have to pay for it to be shipped to me and then shipped to you. That and sales tax would make it cheaper for you to purchase it online I'm afraid.