I bought a radio at www.vintageautoradio.com
for my 1971. It is one like you described, totally looks like the OEM radio but has all new tech and has an AUX input for satellite or ipod. It was only like $180 and was super simple for install. So far I've only got the center dash speaker and the two door speakers hooked up to it but it sounds great. I think that might be your best bet. I'll take a pic later to show you.